CINXE.COM
Office of Weights and Measures | NIST
<!DOCTYPE html> <html lang="en" dir="ltr" prefix="content: http://purl.org/rss/1.0/modules/content/ dc: http://purl.org/dc/terms/ foaf: http://xmlns.com/foaf/0.1/ og: http://ogp.me/ns# rdfs: http://www.w3.org/2000/01/rdf-schema# schema: http://schema.org/ sioc: http://rdfs.org/sioc/ns# sioct: http://rdfs.org/sioc/types# skos: http://www.w3.org/2004/02/skos/core# xsd: http://www.w3.org/2001/XMLSchema# "> <head><script type="text/javascript" src="/_static/js/bundle-playback.js?v=HxkREWBo" charset="utf-8"></script> <script type="text/javascript" src="/_static/js/wombat.js?v=txqj7nKC" charset="utf-8"></script> <script>window.RufflePlayer=window.RufflePlayer||{};window.RufflePlayer.config={"autoplay":"on","unmuteOverlay":"hidden"};</script> <script type="text/javascript" src="/_static/js/ruffle/ruffle.js"></script> <script type="text/javascript"> __wm.init("https://web.archive.org/web"); __wm.wombat("https://www.nist.gov/pml/owm","20231204172920","https://web.archive.org/","web","/_static/", "1701710960"); </script> <link rel="stylesheet" type="text/css" href="/_static/css/banner-styles.css?v=S1zqJCYt" /> <link rel="stylesheet" type="text/css" href="/_static/css/iconochive.css?v=3PDvdIFv" /> <!-- End Wayback Rewrite JS Include --> <meta charset="utf-8"/><script type="text/javascript">(window.NREUM||(NREUM={})).init={ajax:{deny_list:["gov-bam.nr-data.net"]}};(window.NREUM||(NREUM={})).loader_config={licenseKey:"37b7ccb661",applicationID:"1089704227"};;/*! For license information please see nr-loader-rum-1.248.0.min.js.LICENSE.txt */ (()=>{var e,t,n={234:(e,t,n)=>{"use strict";n.d(t,{P_:()=>h,Mt:()=>m,C5:()=>s,DL:()=>w,OP:()=>j,lF:()=>R,Yu:()=>_,Dg:()=>v,CX:()=>c,GE:()=>A,sU:()=>T});var r=n(8632),i=n(9567);const a={beacon:r.ce.beacon,errorBeacon:r.ce.errorBeacon,licenseKey:void 0,applicationID:void 0,sa:void 0,queueTime:void 0,applicationTime:void 0,ttGuid:void 0,user:void 0,account:void 0,product:void 0,extra:void 0,jsAttributes:{},userAttributes:void 0,atts:void 0,transactionName:void 0,tNamePlain:void 0},o={};function s(e){if(!e)throw new Error("All info objects require an agent identifier!");if(!o[e])throw new Error("Info for ".concat(e," was never set"));return o[e]}function c(e,t){if(!e)throw new Error("All info objects require an agent identifier!");o[e]=(0,i.D)(t,a);const n=(0,r.ek)(e);n&&(n.info=o[e])}const u=e=>{if(!e||"string"!=typeof e)return!1;try{document.createDocumentFragment().querySelector(e)}catch{return!1}return!0};var d=n(7056),l=n(50);const f=()=>{const e={mask_selector:"*",block_selector:"[data-nr-block]",mask_input_options:{color:!1,date:!1,"datetime-local":!1,email:!1,month:!1,number:!1,range:!1,search:!1,tel:!1,text:!1,time:!1,url:!1,week:!1,textarea:!1,select:!1,password:!0}};return{feature_flags:[],proxy:{assets:void 0,beacon:void 0},privacy:{cookies_enabled:!0},ajax:{deny_list:void 0,block_internal:!0,enabled:!0,harvestTimeSeconds:10,autoStart:!0},distributed_tracing:{enabled:void 0,exclude_newrelic_header:void 0,cors_use_newrelic_header:void 0,cors_use_tracecontext_headers:void 0,allowed_origins:void 0},session:{domain:void 0,expiresMs:d.oD,inactiveMs:d.Hb},ssl:void 0,obfuscate:void 0,jserrors:{enabled:!0,harvestTimeSeconds:10,autoStart:!0},metrics:{enabled:!0,autoStart:!0},page_action:{enabled:!0,harvestTimeSeconds:30,autoStart:!0},page_view_event:{enabled:!0,autoStart:!0},page_view_timing:{enabled:!0,harvestTimeSeconds:30,long_task:!1,autoStart:!0},session_trace:{enabled:!0,harvestTimeSeconds:10,autoStart:!0},harvest:{tooManyRequestsDelay:60},session_replay:{autoStart:!0,enabled:!1,harvestTimeSeconds:60,sampling_rate:50,error_sampling_rate:50,collect_fonts:!1,inline_images:!1,inline_stylesheet:!0,mask_all_inputs:!0,get mask_text_selector(){return e.mask_selector},set mask_text_selector(t){u(t)?e.mask_selector=t+",[data-nr-mask]":null===t?e.mask_selector=t:(0,l.Z)("An invalid session_replay.mask_selector was provided and will not be used",t)},get block_class(){return"nr-block"},get ignore_class(){return"nr-ignore"},get mask_text_class(){return"nr-mask"},get block_selector(){return e.block_selector},set block_selector(t){u(t)?e.block_selector+=",".concat(t):""!==t&&(0,l.Z)("An invalid session_replay.block_selector was provided and will not be used",t)},get mask_input_options(){return e.mask_input_options},set mask_input_options(t){t&&"object"==typeof t?e.mask_input_options={...t,password:!0}:(0,l.Z)("An invalid session_replay.mask_input_option was provided and will not be used",t)}},spa:{enabled:!0,harvestTimeSeconds:10,autoStart:!0}}},g={},p="All configuration objects require an agent identifier!";function h(e){if(!e)throw new Error(p);if(!g[e])throw new Error("Configuration for ".concat(e," was never set"));return g[e]}function v(e,t){if(!e)throw new Error(p);g[e]=(0,i.D)(t,f());const n=(0,r.ek)(e);n&&(n.init=g[e])}function m(e,t){if(!e)throw new Error(p);var n=h(e);if(n){for(var r=t.split("."),i=0;i<r.length-1;i++)if("object"!=typeof(n=n[r[i]]))return;n=n[r[r.length-1]]}return n}const b={accountID:void 0,trustKey:void 0,agentID:void 0,licenseKey:void 0,applicationID:void 0,xpid:void 0},y={};function w(e){if(!e)throw new Error("All loader-config objects require an agent identifier!");if(!y[e])throw new Error("LoaderConfig for ".concat(e," was never set"));return y[e]}function A(e,t){if(!e)throw new Error("All loader-config objects require an agent identifier!");y[e]=(0,i.D)(t,b);const n=(0,r.ek)(e);n&&(n.loader_config=y[e])}const _=(0,r.mF)().o;var x=n(385),D=n(6818);const k={buildEnv:D.Re,customTransaction:void 0,disabled:!1,distMethod:D.gF,isolatedBacklog:!1,loaderType:void 0,maxBytes:3e4,offset:Math.floor(x._A?.performance?.timeOrigin||x._A?.performance?.timing?.navigationStart||Date.now()),onerror:void 0,origin:""+x._A.location,ptid:void 0,releaseIds:{},session:void 0,xhrWrappable:"function"==typeof x._A.XMLHttpRequest?.prototype?.addEventListener,version:D.q4,denyList:void 0},E={};function j(e){if(!e)throw new Error("All runtime objects require an agent identifier!");if(!E[e])throw new Error("Runtime for ".concat(e," was never set"));return E[e]}function T(e,t){if(!e)throw new Error("All runtime objects require an agent identifier!");E[e]=(0,i.D)(t,k);const n=(0,r.ek)(e);n&&(n.runtime=E[e])}function R(e){return function(e){try{const t=s(e);return!!t.licenseKey&&!!t.errorBeacon&&!!t.applicationID}catch(e){return!1}}(e)}},9567:(e,t,n)=>{"use strict";n.d(t,{D:()=>i});var r=n(50);function i(e,t){try{if(!e||"object"!=typeof e)return(0,r.Z)("Setting a Configurable requires an object as input");if(!t||"object"!=typeof t)return(0,r.Z)("Setting a Configurable requires a model to set its initial properties");const n=Object.create(Object.getPrototypeOf(t),Object.getOwnPropertyDescriptors(t)),a=0===Object.keys(n).length?e:n;for(let o in a)if(void 0!==e[o])try{Array.isArray(e[o])&&Array.isArray(t[o])?n[o]=Array.from(new Set([...e[o],...t[o]])):"object"==typeof e[o]&&"object"==typeof t[o]?n[o]=i(e[o],t[o]):n[o]=e[o]}catch(e){(0,r.Z)("An error occurred while setting a property of a Configurable",e)}return n}catch(e){(0,r.Z)("An error occured while setting a Configurable",e)}}},6818:(e,t,n)=>{"use strict";n.d(t,{Re:()=>i,gF:()=>a,q4:()=>r});const r="1.248.0",i="PROD",a="CDN"},385:(e,t,n)=>{"use strict";n.d(t,{Nk:()=>d,Tt:()=>s,_A:()=>a,cv:()=>l,iS:()=>o,il:()=>r,ux:()=>c,v6:()=>i,w1:()=>u});const r="undefined"!=typeof window&&!!window.document,i="undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self.navigator instanceof WorkerNavigator||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis.navigator instanceof WorkerNavigator),a=r?window:"undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis),o=(a?.document?.readyState,Boolean("hidden"===a?.document?.visibilityState)),s=(a?.location,/iPad|iPhone|iPod/.test(a.navigator?.userAgent)),c=s&&"undefined"==typeof SharedWorker,u=((()=>{const e=a.navigator?.userAgent?.match(/Firefox[/\s](\d+\.\d+)/);Array.isArray(e)&&e.length>=2&&e[1]})(),Boolean(r&&window.document.documentMode)),d=!!a.navigator?.sendBeacon,l=Math.floor(a?.performance?.timeOrigin||a?.performance?.timing?.navigationStart||Date.now())},1117:(e,t,n)=>{"use strict";n.d(t,{w:()=>a});var r=n(50);const i={agentIdentifier:"",ee:void 0};class a{constructor(e){try{if("object"!=typeof e)return(0,r.Z)("shared context requires an object as input");this.sharedContext={},Object.assign(this.sharedContext,i),Object.entries(e).forEach((e=>{let[t,n]=e;Object.keys(i).includes(t)&&(this.sharedContext[t]=n)}))}catch(e){(0,r.Z)("An error occured while setting SharedContext",e)}}}},8e3:(e,t,n)=>{"use strict";n.d(t,{L:()=>d,R:()=>c});var r=n(8325),i=n(1284),a=n(4322),o=n(3325);const s={};function c(e,t){const n={staged:!1,priority:o.p[t]||0};u(e),s[e].get(t)||s[e].set(t,n)}function u(e){e&&(s[e]||(s[e]=new Map))}function d(){let e=arguments.length>0&&void 0!==arguments[0]?arguments[0]:"",t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:"feature";if(u(e),!e||!s[e].get(t))return o(t);s[e].get(t).staged=!0;const n=[...s[e]];function o(t){const n=e?r.ee.get(e):r.ee,o=a.X.handlers;if(n.backlog&&o){var s=n.backlog[t],c=o[t];if(c){for(var u=0;s&&u<s.length;++u)l(s[u],c);(0,i.D)(c,(function(e,t){(0,i.D)(t,(function(t,n){n[0].on(e,n[1])}))}))}delete o[t],n.backlog[t]=null,n.emit("drain-"+t,[])}}n.every((e=>{let[t,n]=e;return n.staged}))&&(n.sort(((e,t)=>e[1].priority-t[1].priority)),n.forEach((t=>{let[n]=t;s[e].delete(n),o(n)})))}function l(e,t){var n=e[1];(0,i.D)(t[n],(function(t,n){var r=e[0];if(n[0]===r){var i=n[1],a=e[3],o=e[2];i.apply(a,o)}}))}},8325:(e,t,n)=>{"use strict";n.d(t,{A:()=>c,ee:()=>u});var r=n(8632),i=n(2210),a=n(234);class o{constructor(e){this.contextId=e}}var s=n(3117);const c="nr@context:".concat(s.a),u=function e(t,n){var r={},s={},d={},f=!1;try{f=16===n.length&&(0,a.OP)(n).isolatedBacklog}catch(e){}var g={on:h,addEventListener:h,removeEventListener:function(e,t){var n=r[e];if(!n)return;for(var i=0;i<n.length;i++)n[i]===t&&n.splice(i,1)},emit:function(e,n,r,i,a){!1!==a&&(a=!0);if(u.aborted&&!i)return;t&&a&&t.emit(e,n,r);for(var o=p(r),c=v(e),d=c.length,l=0;l<d;l++)c[l].apply(o,n);var f=b()[s[e]];f&&f.push([g,e,n,o]);return o},get:m,listeners:v,context:p,buffer:function(e,t){const n=b();if(t=t||"feature",g.aborted)return;Object.entries(e||{}).forEach((e=>{let[r,i]=e;s[i]=t,t in n||(n[t]=[])}))},abort:l,aborted:!1,isBuffering:function(e){return!!b()[s[e]]},debugId:n,backlog:f?{}:t&&"object"==typeof t.backlog?t.backlog:{}};return g;function p(e){return e&&e instanceof o?e:e?(0,i.X)(e,c,(()=>new o(c))):new o(c)}function h(e,t){r[e]=v(e).concat(t)}function v(e){return r[e]||[]}function m(t){return d[t]=d[t]||e(g,t)}function b(){return g.backlog}}(void 0,"globalEE"),d=(0,r.fP)();function l(){u.aborted=!0,u.backlog={}}d.ee||(d.ee=u)},5546:(e,t,n)=>{"use strict";n.d(t,{E:()=>r,p:()=>i});var r=n(8325).ee.get("handle");function i(e,t,n,i,a){a?(a.buffer([e],i),a.emit(e,t,n)):(r.buffer([e],i),r.emit(e,t,n))}},4322:(e,t,n)=>{"use strict";n.d(t,{X:()=>a});var r=n(5546);a.on=o;var i=a.handlers={};function a(e,t,n,a){o(a||r.E,i,e,t,n)}function o(e,t,n,i,a){a||(a="feature"),e||(e=r.E);var o=t[a]=t[a]||{};(o[n]=o[n]||[]).push([e,i])}},3239:(e,t,n)=>{"use strict";n.d(t,{bP:()=>s,iz:()=>c,m$:()=>o});var r=n(385);let i=!1,a=!1;try{const e={get passive(){return i=!0,!1},get signal(){return a=!0,!1}};r._A.addEventListener("test",null,e),r._A.removeEventListener("test",null,e)}catch(e){}function o(e,t){return i||a?{capture:!!e,passive:i,signal:t}:!!e}function s(e,t){let n=arguments.length>2&&void 0!==arguments[2]&&arguments[2],r=arguments.length>3?arguments[3]:void 0;window.addEventListener(e,t,o(n,r))}function c(e,t){let n=arguments.length>2&&void 0!==arguments[2]&&arguments[2],r=arguments.length>3?arguments[3]:void 0;document.addEventListener(e,t,o(n,r))}},3117:(e,t,n)=>{"use strict";n.d(t,{a:()=>r});const r=(0,n(4402).Rl)()},4402:(e,t,n)=>{"use strict";n.d(t,{Rl:()=>o,ky:()=>s});var r=n(385);const i="xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx";function a(e,t){return e?15&e[t]:16*Math.random()|0}function o(){const e=r._A?.crypto||r._A?.msCrypto;let t,n=0;return e&&e.getRandomValues&&(t=e.getRandomValues(new Uint8Array(31))),i.split("").map((e=>"x"===e?a(t,++n).toString(16):"y"===e?(3&a()|8).toString(16):e)).join("")}function s(e){const t=r._A?.crypto||r._A?.msCrypto;let n,i=0;t&&t.getRandomValues&&(n=t.getRandomValues(new Uint8Array(31)));const o=[];for(var s=0;s<e;s++)o.push(a(n,++i).toString(16));return o.join("")}},7056:(e,t,n)=>{"use strict";n.d(t,{Bq:()=>r,Hb:()=>a,oD:()=>i});const r="NRBA",i=144e5,a=18e5},7894:(e,t,n)=>{"use strict";function r(){return Math.round(performance.now())}n.d(t,{z:()=>r})},50:(e,t,n)=>{"use strict";function r(e,t){"function"==typeof console.warn&&(console.warn("New Relic: ".concat(e)),t&&console.warn(t))}n.d(t,{Z:()=>r})},2825:(e,t,n)=>{"use strict";n.d(t,{N:()=>d,T:()=>l});var r=n(8325),i=n(5546),a=n(3325),o=n(385);const s="newrelic";const c={stn:[a.D.sessionTrace],err:[a.D.jserrors,a.D.metrics],ins:[a.D.pageAction],spa:[a.D.spa],sr:[a.D.sessionReplay,a.D.sessionTrace]},u=new Set;function d(e,t){const n=r.ee.get(t);e&&"object"==typeof e&&(u.has(t)||(Object.entries(e).forEach((e=>{let[t,r]=e;c[t]?c[t].forEach((e=>{r?(0,i.p)("feat-"+t,[],void 0,e,n):(0,i.p)("block-"+t,[],void 0,e,n),(0,i.p)("rumresp-"+t,[Boolean(r)],void 0,e,n)})):r&&(0,i.p)("feat-"+t,[],void 0,void 0,n),l[t]=Boolean(r)})),Object.keys(c).forEach((e=>{void 0===l[e]&&(c[e]?.forEach((t=>(0,i.p)("rumresp-"+e,[!1],void 0,t,n))),l[e]=!1)})),u.add(t),function(){let e=arguments.length>0&&void 0!==arguments[0]?arguments[0]:{};try{o._A.dispatchEvent(new CustomEvent(s,{detail:e}))}catch(e){}}({loaded:!0})))}const l={}},2210:(e,t,n)=>{"use strict";n.d(t,{X:()=>i});var r=Object.prototype.hasOwnProperty;function i(e,t,n){if(r.call(e,t))return e[t];var i=n();if(Object.defineProperty&&Object.keys)try{return Object.defineProperty(e,t,{value:i,writable:!0,enumerable:!1}),i}catch(e){}return e[t]=i,i}},1284:(e,t,n)=>{"use strict";n.d(t,{D:()=>r});const r=(e,t)=>Object.entries(e||{}).map((e=>{let[n,r]=e;return t(n,r)}))},4351:(e,t,n)=>{"use strict";n.d(t,{P:()=>a});var r=n(8325);const i=()=>{const e=new WeakSet;return(t,n)=>{if("object"==typeof n&&null!==n){if(e.has(n))return;e.add(n)}return n}};function a(e){try{return JSON.stringify(e,i())}catch(e){try{r.ee.emit("internal-error",[e])}catch(e){}}}},3960:(e,t,n)=>{"use strict";n.d(t,{KB:()=>o,b2:()=>a});var r=n(3239);function i(){return"undefined"==typeof document||"complete"===document.readyState}function a(e,t){if(i())return e();(0,r.bP)("load",e,t)}function o(e){if(i())return e();(0,r.iz)("DOMContentLoaded",e)}},8632:(e,t,n)=>{"use strict";n.d(t,{EZ:()=>d,ce:()=>a,ek:()=>u,fP:()=>o,gG:()=>l,h5:()=>c,mF:()=>s});var r=n(7894),i=n(385);const a={beacon:"bam.nr-data.net",errorBeacon:"bam.nr-data.net"};function o(){return i._A.NREUM||(i._A.NREUM={}),void 0===i._A.newrelic&&(i._A.newrelic=i._A.NREUM),i._A.NREUM}function s(){let e=o();return e.o||(e.o={ST:i._A.setTimeout,SI:i._A.setImmediate,CT:i._A.clearTimeout,XHR:i._A.XMLHttpRequest,REQ:i._A.Request,EV:i._A.Event,PR:i._A.Promise,MO:i._A.MutationObserver,FETCH:i._A.fetch}),e}function c(e,t){let n=o();n.initializedAgents??={},t.initializedAt={ms:(0,r.z)(),date:new Date},n.initializedAgents[e]=t}function u(e){let t=o();return t.initializedAgents?.[e]}function d(e,t){o()[e]=t}function l(){return function(){let e=o();const t=e.info||{};e.info={beacon:a.beacon,errorBeacon:a.errorBeacon,...t}}(),function(){let e=o();const t=e.init||{};e.init={...t}}(),s(),function(){let e=o();const t=e.loader_config||{};e.loader_config={...t}}(),o()}},7956:(e,t,n)=>{"use strict";n.d(t,{N:()=>i});var r=n(3239);function i(e){let t=arguments.length>1&&void 0!==arguments[1]&&arguments[1],n=arguments.length>2?arguments[2]:void 0,i=arguments.length>3?arguments[3]:void 0;(0,r.iz)("visibilitychange",(function(){if(t)return void("hidden"===document.visibilityState&&e());e(document.visibilityState)}),n,i)}},3081:(e,t,n)=>{"use strict";n.d(t,{gF:()=>a,mY:()=>i,t9:()=>r,vz:()=>s,xS:()=>o});const r=n(3325).D.metrics,i="sm",a="cm",o="storeSupportabilityMetrics",s="storeEventMetrics"},7633:(e,t,n)=>{"use strict";n.d(t,{t:()=>r});const r=n(3325).D.pageViewEvent},9251:(e,t,n)=>{"use strict";n.d(t,{t:()=>r});const r=n(3325).D.pageViewTiming},5938:(e,t,n)=>{"use strict";n.d(t,{W:()=>i});var r=n(8325);class i{constructor(e,t,n){this.agentIdentifier=e,this.aggregator=t,this.ee=r.ee.get(e),this.featureName=n,this.blocked=!1}}},7530:(e,t,n)=>{"use strict";n.d(t,{j:()=>b});var r=n(3325),i=n(234),a=n(5546),o=n(8325),s=n(7894),c=n(8e3),u=n(3960),d=n(385),l=n(50),f=n(3081),g=n(8632);function p(){const e=(0,g.gG)();["setErrorHandler","finished","addToTrace","addRelease","addPageAction","setCurrentRouteName","setPageViewName","setCustomAttribute","interaction","noticeError","setUserId","setApplicationVersion","start","recordReplay","pauseReplay"].forEach((t=>{e[t]=function(){for(var n=arguments.length,r=new Array(n),i=0;i<n;i++)r[i]=arguments[i];return function(t){for(var n=arguments.length,r=new Array(n>1?n-1:0),i=1;i<n;i++)r[i-1]=arguments[i];let a=[];return Object.values(e.initializedAgents).forEach((e=>{e.exposed&&e.api[t]&&a.push(e.api[t](...r))})),a.length>1?a:a[0]}(t,...r)}}))}var h=n(2825);const v=e=>{const t=e.startsWith("http");e+="/",n.p=t?e:"https://"+e};let m=!1;function b(e){let t=arguments.length>1&&void 0!==arguments[1]?arguments[1]:{},b=arguments.length>2?arguments[2]:void 0,y=arguments.length>3?arguments[3]:void 0,{init:w,info:A,loader_config:_,runtime:x={loaderType:b},exposed:D=!0}=t;const k=(0,g.gG)();A||(w=k.init,A=k.info,_=k.loader_config),(0,i.Dg)(e.agentIdentifier,w||{}),(0,i.GE)(e.agentIdentifier,_||{}),A.jsAttributes??={},d.v6&&(A.jsAttributes.isWorker=!0),(0,i.CX)(e.agentIdentifier,A);const E=(0,i.P_)(e.agentIdentifier),j=[A.beacon,A.errorBeacon];m||(E.proxy.assets&&(v(E.proxy.assets),j.push(E.proxy.assets)),E.proxy.beacon&&j.push(E.proxy.beacon),p(),(0,g.EZ)("activatedFeatures",h.T)),x.denyList=[...E.ajax.deny_list||[],...E.ajax.block_internal?j:[]],(0,i.sU)(e.agentIdentifier,x),void 0===e.api&&(e.api=function(e,t){t||(0,c.R)(e,"api");const g={};var p=o.ee.get(e),h=p.get("tracer"),v="api-",m=v+"ixn-";function b(t,n,r,a){const o=(0,i.C5)(e);return null===n?delete o.jsAttributes[t]:(0,i.CX)(e,{...o,jsAttributes:{...o.jsAttributes,[t]:n}}),A(v,r,!0,a||null===n?"session":void 0)(t,n)}function y(){}["setErrorHandler","finished","addToTrace","addRelease"].forEach((e=>{g[e]=A(v,e,!0,"api")})),g.addPageAction=A(v,"addPageAction",!0,r.D.pageAction),g.setCurrentRouteName=A(v,"routeName",!0,r.D.spa),g.setPageViewName=function(t,n){if("string"==typeof t)return"/"!==t.charAt(0)&&(t="/"+t),(0,i.OP)(e).customTransaction=(n||"https://web.archive.org/web/20231204172920/http://custom.transaction")+t,A(v,"setPageViewName",!0)()},g.setCustomAttribute=function(e,t){let n=arguments.length>2&&void 0!==arguments[2]&&arguments[2];if("string"==typeof e){if(["string","number","boolean"].includes(typeof t)||null===t)return b(e,t,"setCustomAttribute",n);(0,l.Z)("Failed to execute setCustomAttribute.\nNon-null value must be a string, number or boolean type, but a type of <".concat(typeof t,"> was provided."))}else(0,l.Z)("Failed to execute setCustomAttribute.\nName must be a string type, but a type of <".concat(typeof e,"> was provided."))},g.setUserId=function(e){if("string"==typeof e||null===e)return b("enduser.id",e,"setUserId",!0);(0,l.Z)("Failed to execute setUserId.\nNon-null value must be a string type, but a type of <".concat(typeof e,"> was provided."))},g.setApplicationVersion=function(e){if("string"==typeof e||null===e)return b("application.version",e,"setApplicationVersion",!1);(0,l.Z)("Failed to execute setApplicationVersion. Expected <String | null>, but got <".concat(typeof e,">."))},g.start=e=>{try{const t=e?"defined":"undefined";(0,a.p)(f.xS,["API/start/".concat(t,"/called")],void 0,r.D.metrics,p);const n=Object.values(r.D);if(void 0===e)e=n;else{if((e=Array.isArray(e)&&e.length?e:[e]).some((e=>!n.includes(e))))return(0,l.Z)("Invalid feature name supplied. Acceptable feature names are: ".concat(n));e.includes(r.D.pageViewEvent)||e.push(r.D.pageViewEvent)}e.forEach((e=>{p.emit("".concat(e,"-opt-in"))}))}catch(e){(0,l.Z)("An unexpected issue occurred",e)}},g.recordReplay=function(){(0,a.p)(f.xS,["API/recordReplay/called"],void 0,r.D.metrics,p),(0,a.p)("recordReplay",[],void 0,r.D.sessionReplay,p)},g.pauseReplay=function(){(0,a.p)(f.xS,["API/pauseReplay/called"],void 0,r.D.metrics,p),(0,a.p)("pauseReplay",[],void 0,r.D.sessionReplay,p)},g.interaction=function(){return(new y).get()};var w=y.prototype={createTracer:function(e,t){var n={},i=this,o="function"==typeof t;return(0,a.p)(f.xS,["API/createTracer/called"],void 0,r.D.metrics,p),(0,a.p)(m+"tracer",[(0,s.z)(),e,n],i,r.D.spa,p),function(){if(h.emit((o?"":"no-")+"fn-start",[(0,s.z)(),i,o],n),o)try{return t.apply(this,arguments)}catch(e){throw h.emit("fn-err",[arguments,this,e],n),e}finally{h.emit("fn-end",[(0,s.z)()],n)}}}};function A(e,t,n,i){return function(){return(0,a.p)(f.xS,["API/"+t+"/called"],void 0,r.D.metrics,p),i&&(0,a.p)(e+t,[(0,s.z)(),...arguments],n?null:this,i,p),n?void 0:this}}function _(){n.e(75).then(n.bind(n,7438)).then((t=>{let{setAPI:n}=t;n(e),(0,c.L)(e,"api")})).catch((()=>(0,l.Z)("Downloading runtime APIs failed...")))}return["actionText","setName","setAttribute","save","ignore","onEnd","getContext","end","get"].forEach((e=>{w[e]=A(m,e,void 0,r.D.spa)})),g.noticeError=function(e,t){"string"==typeof e&&(e=new Error(e)),(0,a.p)(f.xS,["API/noticeError/called"],void 0,r.D.metrics,p),(0,a.p)("err",[e,(0,s.z)(),!1,t],void 0,r.D.jserrors,p)},d.il?(0,u.b2)((()=>_()),!0):_(),g}(e.agentIdentifier,y)),void 0===e.exposed&&(e.exposed=D),m=!0}},1926:(e,t,n)=>{n.nc=(()=>{try{return document?.currentScript?.nonce}catch(e){}return""})()},3325:(e,t,n)=>{"use strict";n.d(t,{D:()=>r,p:()=>i});const r={ajax:"ajax",jserrors:"jserrors",metrics:"metrics",pageAction:"page_action",pageViewEvent:"page_view_event",pageViewTiming:"page_view_timing",sessionReplay:"session_replay",sessionTrace:"session_trace",spa:"spa"},i={[r.pageViewEvent]:1,[r.pageViewTiming]:2,[r.metrics]:3,[r.jserrors]:4,[r.ajax]:5,[r.sessionTrace]:6,[r.pageAction]:7,[r.spa]:8,[r.sessionReplay]:9}}},r={};function i(e){var t=r[e];if(void 0!==t)return t.exports;var a=r[e]={exports:{}};return n[e](a,a.exports,i),a.exports}i.m=n,i.d=(e,t)=>{for(var n in t)i.o(t,n)&&!i.o(e,n)&&Object.defineProperty(e,n,{enumerable:!0,get:t[n]})},i.f={},i.e=e=>Promise.all(Object.keys(i.f).reduce(((t,n)=>(i.f[n](e,t),t)),[])),i.u=e=>"nr-rum-1.248.0.min.js",i.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),e={},t="NRBA-1.248.0.PROD:",i.l=(n,r,a,o)=>{if(e[n])e[n].push(r);else{var s,c;if(void 0!==a)for(var u=document.getElementsByTagName("script"),d=0;d<u.length;d++){var l=u[d];if(l.getAttribute("src")==n||l.getAttribute("data-webpack")==t+a){s=l;break}}s||(c=!0,(s=document.createElement("script")).charset="utf-8",s.timeout=120,i.nc&&s.setAttribute("nonce",i.nc),s.setAttribute("data-webpack",t+a),s.src=n,0!==s.src.indexOf(window.location.origin+"/")&&(s.crossOrigin="anonymous"),s.integrity=i.sriHashes[o],s.crossOrigin="anonymous"),e[n]=[r];var f=(t,r)=>{s.onerror=s.onload=null,clearTimeout(g);var i=e[n];if(delete e[n],s.parentNode&&s.parentNode.removeChild(s),i&&i.forEach((e=>e(r))),t)return t(r)},g=setTimeout(f.bind(null,void 0,{type:"timeout",target:s}),12e4);s.onerror=f.bind(null,s.onerror),s.onload=f.bind(null,s.onload),c&&document.head.appendChild(s)}},i.r=e=>{"undefined"!=typeof Symbol&&Symbol.toStringTag&&Object.defineProperty(e,Symbol.toStringTag,{value:"Module"}),Object.defineProperty(e,"__esModule",{value:!0})},i.p="https://web.archive.org/web/20231204172920/https://js-agent.newrelic.com/",i.sriHashes={75:"sha512-5mWtMwj7hrXT5aUkfvBtjH6FJXsR+zdeMBfc721nzrOx36xa23yTrCB1VVOAQa+zIioAbWPW4m7UsPp7hW1WPw=="},(()=>{var e={50:0,832:0};i.f.j=(t,n)=>{var r=i.o(e,t)?e[t]:void 0;if(0!==r)if(r)n.push(r[2]);else{var a=new Promise(((n,i)=>r=e[t]=[n,i]));n.push(r[2]=a);var o=i.p+i.u(t),s=new Error;i.l(o,(n=>{if(i.o(e,t)&&(0!==(r=e[t])&&(e[t]=void 0),r)){var a=n&&("load"===n.type?"missing":n.type),o=n&&n.target&&n.target.src;s.message="Loading chunk "+t+" failed.\n("+a+": "+o+")",s.name="ChunkLoadError",s.type=a,s.request=o,r[1](s)}}),"chunk-"+t,t)}};var t=(t,n)=>{var r,a,[o,s,c]=n,u=0;if(o.some((t=>0!==e[t]))){for(r in s)i.o(s,r)&&(i.m[r]=s[r]);if(c)c(i)}for(t&&t(n);u<o.length;u++)a=o[u],i.o(e,a)&&e[a]&&e[a][0](),e[a]=0},n=self["webpackChunk:NRBA-1.248.0.PROD"]=self["webpackChunk:NRBA-1.248.0.PROD"]||[];n.forEach(t.bind(null,0)),n.push=t.bind(null,n.push.bind(n))})(),(()=>{"use strict";i(1926);var e=i(50);class t{addPageAction(t,n){(0,e.Z)("Call to agent api addPageAction failed. The page action feature is not currently initialized.")}setPageViewName(t,n){(0,e.Z)("Call to agent api setPageViewName failed. The page view feature is not currently initialized.")}setCustomAttribute(t,n,r){(0,e.Z)("Call to agent api setCustomAttribute failed. The js errors feature is not currently initialized.")}noticeError(t,n){(0,e.Z)("Call to agent api noticeError failed. The js errors feature is not currently initialized.")}setUserId(t){(0,e.Z)("Call to agent api setUserId failed. The js errors feature is not currently initialized.")}setApplicationVersion(t){(0,e.Z)("Call to agent api setApplicationVersion failed. The agent is not currently initialized.")}setErrorHandler(t){(0,e.Z)("Call to agent api setErrorHandler failed. The js errors feature is not currently initialized.")}finished(t){(0,e.Z)("Call to agent api finished failed. The page action feature is not currently initialized.")}addRelease(t,n){(0,e.Z)("Call to agent api addRelease failed. The js errors feature is not currently initialized.")}start(t){(0,e.Z)("Call to agent api addRelease failed. The agent is not currently initialized.")}recordReplay(){(0,e.Z)("Call to agent api recordReplay failed. The agent is not currently initialized.")}pauseReplay(){(0,e.Z)("Call to agent api pauseReplay failed. The agent is not currently initialized.")}}var n=i(3325),r=i(234);const a=Object.values(n.D);function o(e){const t={};return a.forEach((n=>{t[n]=function(e,t){return!1!==(0,r.Mt)(t,"".concat(e,".enabled"))}(n,e)})),t}var s=i(7530);var c=i(8e3),u=i(5938),d=i(3960),l=i(385);class f extends u.W{constructor(e,t,n){let i=!(arguments.length>3&&void 0!==arguments[3])||arguments[3];super(e,t,n),this.auto=i,this.abortHandler=void 0,this.featAggregate=void 0,this.onAggregateImported=void 0,!1===(0,r.Mt)(this.agentIdentifier,"".concat(this.featureName,".autoStart"))&&(this.auto=!1),this.auto&&(0,c.R)(e,n)}importAggregator(){let t=arguments.length>0&&void 0!==arguments[0]?arguments[0]:{};if(this.featAggregate)return;if(!this.auto)return void this.ee.on("".concat(this.featureName,"-opt-in"),(()=>{(0,c.R)(this.agentIdentifier,this.featureName),this.auto=!0,this.importAggregator()}));const n=l.il&&!0===(0,r.Mt)(this.agentIdentifier,"privacy.cookies_enabled");let a;this.onAggregateImported=new Promise((e=>{a=e}));const o=async()=>{let r;try{if(n){const{setupAgentSession:e}=await i.e(75).then(i.bind(i,3228));r=e(this.agentIdentifier)}}catch(t){(0,e.Z)("A problem occurred when starting up session manager. This page will not start or extend any session.",t)}try{if(!this.shouldImportAgg(this.featureName,r))return(0,c.L)(this.agentIdentifier,this.featureName),void a(!1);const{lazyFeatureLoader:e}=await i.e(75).then(i.bind(i,8582)),{Aggregate:n}=await e(this.featureName,"aggregate");this.featAggregate=new n(this.agentIdentifier,this.aggregator,t),a(!0)}catch(t){(0,e.Z)("Downloading and initializing ".concat(this.featureName," failed..."),t),this.abortHandler?.(),(0,c.L)(this.agentIdentifier,this.featureName),a(!1)}};l.il?(0,d.b2)((()=>o()),!0):o()}shouldImportAgg(e,t){return e!==n.D.sessionReplay||!!r.Yu.MO&&(!1!==(0,r.Mt)(this.agentIdentifier,"session_trace.enabled")&&(!!t?.isNew||!!t?.state.sessionReplayMode))}}var g=i(7633);class p extends f{static featureName=g.t;constructor(e,t){let n=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,g.t,n),this.importAggregator()}}var h=i(1117),v=i(1284);class m extends h.w{constructor(e){super(e),this.aggregatedData={}}store(e,t,n,r,i){var a=this.getBucket(e,t,n,i);return a.metrics=function(e,t){t||(t={count:0});return t.count+=1,(0,v.D)(e,(function(e,n){t[e]=b(n,t[e])})),t}(r,a.metrics),a}merge(e,t,n,r,i){var a=this.getBucket(e,t,r,i);if(a.metrics){var o=a.metrics;o.count+=n.count,(0,v.D)(n,(function(e,t){if("count"!==e){var r=o[e],i=n[e];i&&!i.c?o[e]=b(i.t,r):o[e]=function(e,t){if(!t)return e;t.c||(t=y(t.t));return t.min=Math.min(e.min,t.min),t.max=Math.max(e.max,t.max),t.t+=e.t,t.sos+=e.sos,t.c+=e.c,t}(i,o[e])}}))}else a.metrics=n}storeMetric(e,t,n,r){var i=this.getBucket(e,t,n);return i.stats=b(r,i.stats),i}getBucket(e,t,n,r){this.aggregatedData[e]||(this.aggregatedData[e]={});var i=this.aggregatedData[e][t];return i||(i=this.aggregatedData[e][t]={params:n||{}},r&&(i.custom=r)),i}get(e,t){return t?this.aggregatedData[e]&&this.aggregatedData[e][t]:this.aggregatedData[e]}take(e){for(var t={},n="",r=!1,i=0;i<e.length;i++)t[n=e[i]]=w(this.aggregatedData[n]),t[n].length&&(r=!0),delete this.aggregatedData[n];return r?t:null}}function b(e,t){return null==e?function(e){e?e.c++:e={c:1};return e}(t):t?(t.c||(t=y(t.t)),t.c+=1,t.t+=e,t.sos+=e*e,e>t.max&&(t.max=e),e<t.min&&(t.min=e),t):{t:e}}function y(e){return{t:e,min:e,max:e,sos:e*e,c:1}}function w(e){return"object"!=typeof e?[]:(0,v.D)(e,A)}function A(e,t){return t}var _=i(8632),x=i(4402),D=i(4351);var k=i(5546),E=i(7956),j=i(3239),T=i(7894),R=i(9251);class S extends f{static featureName=R.t;constructor(e,t){let n=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,R.t,n),l.il&&((0,E.N)((()=>(0,k.p)("docHidden",[(0,T.z)()],void 0,R.t,this.ee)),!0),(0,j.bP)("pagehide",(()=>(0,k.p)("winPagehide",[(0,T.z)()],void 0,R.t,this.ee))),this.importAggregator())}}var I=i(3081);class C extends f{static featureName=I.t9;constructor(e,t){let n=!(arguments.length>2&&void 0!==arguments[2])||arguments[2];super(e,t,I.t9,n),this.importAggregator()}}new class extends t{constructor(t){let n=arguments.length>1&&void 0!==arguments[1]?arguments[1]:(0,x.ky)(16);super(),l._A?(this.agentIdentifier=n,this.sharedAggregator=new m({agentIdentifier:this.agentIdentifier}),this.features={},(0,_.h5)(n,this),this.desiredFeatures=new Set(t.features||[]),this.desiredFeatures.add(p),(0,s.j)(this,t,t.loaderType||"agent"),this.run()):(0,e.Z)("Failed to initial the agent. Could not determine the runtime environment.")}get config(){return{info:(0,r.C5)(this.agentIdentifier),init:(0,r.P_)(this.agentIdentifier),loader_config:(0,r.DL)(this.agentIdentifier),runtime:(0,r.OP)(this.agentIdentifier)}}run(){try{const t=o(this.agentIdentifier),r=[...this.desiredFeatures];r.sort(((e,t)=>n.p[e.featureName]-n.p[t.featureName])),r.forEach((r=>{if(t[r.featureName]||r.featureName===n.D.pageViewEvent){const i=function(e){switch(e){case n.D.ajax:return[n.D.jserrors];case n.D.sessionTrace:return[n.D.ajax,n.D.pageViewEvent];case n.D.sessionReplay:return[n.D.sessionTrace];case n.D.pageViewTiming:return[n.D.pageViewEvent];default:return[]}}(r.featureName);i.every((e=>t[e]))||(0,e.Z)("".concat(r.featureName," is enabled but one or more dependent features has been disabled (").concat((0,D.P)(i),"). This may cause unintended consequences or missing data...")),this.features[r.featureName]=new r(this.agentIdentifier,this.sharedAggregator)}}))}catch(t){(0,e.Z)("Failed to initialize all enabled instrument classes (agent aborted) -",t);for(const e in this.features)this.features[e].abortHandler?.();const n=(0,_.fP)();return delete n.initializedAgents[this.agentIdentifier]?.api,delete n.initializedAgents[this.agentIdentifier]?.features,delete this.sharedAggregator,n.ee?.abort(),delete n.ee?.get(this.agentIdentifier),!1}}addToTrace(t){(0,e.Z)("Call to agent api addToTrace failed. The session trace feature is not currently initialized.")}setCurrentRouteName(t){(0,e.Z)("Call to agent api setCurrentRouteName failed. The spa feature is not currently initialized.")}interaction(){(0,e.Z)("Call to agent api interaction failed. The spa feature is not currently initialized.")}}({features:[p,S,C],loaderType:"lite"})})()})();</script> <noscript><style>form.antibot * :not(.antibot-message) { display: none !important; }</style> </noscript><script async src="https://web.archive.org/web/20231204172920js_/https://www.googletagmanager.com/gtag/js?id=G-HEQ0YF2VYL"></script> <script>window.dataLayer = window.dataLayer || [];function gtag(){dataLayer.push(arguments)};gtag("js", new Date());gtag("set", "developer_id.dMDhkMT", true);gtag('set', {'cookie_flags': 'SameSite=None;Secure', 'cookie_domain': 'www.nist.gov'});gtag("config", "G-HEQ0YF2VYL", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("event", "custom", {"node_title":"Office of Weights and Measures","node_id":"411896","content_type":"Laboratory\/Organizational Unit"});</script> <meta name="description" content="OWM establishes uniformity, equity, SI use, and traceability in weights and measures by advancing national and international legal metrology standards, procedures, capabilities, and training."/> <link rel="canonical" href="https://web.archive.org/web/20231204172920/https://www.nist.gov/pml/owm"/> <link rel="shortlink" href="https://web.archive.org/web/20231204172920/https://www.nist.gov/node/411896"/> <meta name="citation_title" content="Office of Weights and Measures | NIST"/> <meta property="og:site_name" content="NIST"/> <meta property="og:type" content="Article"/> <meta property="og:url" content="https://web.archive.org/web/20231204172920/https://www.nist.gov/pml/owm"/> <meta property="og:title" content="Office of Weights and Measures"/> <meta property="og:description" content="OWM establishes uniformity, equity, SI use, and traceability in weights and measures by advancing national and international legal metrology standards, procedures, capabilities, and training."/> <meta property="article:published_time" content="2009-07-27T09:48-04:00"/> <meta property="article:modified_time" content="2023-08-30T12:58-04:00"/> <meta name="dcterms.title" content="Office of Weights and Measures"/> <meta name="dcterms.description" content="OWM establishes uniformity, equity, SI use, and traceability in weights and measures by advancing national and international legal metrology standards, procedures, capabilities, and training."/> <meta name="dcterms.date" content="2009-07-27T09:48-04:00"/> <meta name="dcterms.type" content="text"/> <meta name="dcterms.format" content="text/html"/> <meta name="dcterms.identifier" content="https://www.nist.gov/pml/owm"/> <meta name="dcterms.source" content="NIST"/> <meta name="dcterms.created" content="2009-07-27T09:48-04:00"/> <meta name="dcterms.modified" content="2023-08-30T12:58-04:00"/> <meta name="twitter:card" content="summary_large_image"/> <meta name="twitter:description" content="OWM establishes uniformity, equity, SI use, and traceability in weights and measures by advancing national and international legal metrology standards, procedures, capabilities, and training."/> <meta name="twitter:site" content="NIST"/> <meta name="twitter:title" content="Office of Weights and Measures"/> <meta name="twitter:url" content="https://web.archive.org/web/20231204172920im_/https://www.nist.gov/pml/owm"/> <meta name="google-site-verification" content="QMu0ODkER3rN5hLcMLqNVf7e3bkjYsNLTuhqfH48jCA"/> <meta name="Generator" content="Drupal 10 (https://www.drupal.org)"/> <meta name="MobileOptimized" content="width"/> <meta name="HandheldFriendly" content="true"/> <meta name="viewport" content="width=device-width, initial-scale=1.0"/> <meta name="nist_search_modified" class="elastic" content="2023-08-30T12:58:00-04:00"/> <script type="application/ld+json">{ "@context": "https://web.archive.org/web/20231204172920/https://schema.org", "@graph": [ { "@type": "Article", "headline": "Office of Weights and Measures | NIST", "description": "OWM establishes uniformity, equity, SI use, and traceability in weights and measures by advancing national and international legal metrology standards, procedures, capabilities, and training.", "datePublished": "2009-07-27T09:48-04:00", "dateModified": "2023-08-30T12:58-04:00" } ] }</script> <meta name="nist_search_bundle" class="elastic" content="laboratory_organizational_unit"/> <link rel="icon" href="/web/20231204172920im_/https://www.nist.gov/themes/custom/nist_www/favicon.ico" type="image/vnd.microsoft.icon"/> <title>Office of Weights and Measures | NIST</title> <link rel="stylesheet" media="all" href="/web/20231204172920cs_/https://www.nist.gov/sites/default/files/css/css_UrPxtosE0KjcGdsozKaHN4oFNt2iqvKL8y6_YMPICS4.css?delta=0&language=en&theme=nist_www&include=eJx1kYGuwyAIRX_IVz_JUMuUzYoTXNe_X9utabPlJYbA4QZu0HNFe703rLPpwd-c8vKKPeXuKv-2yHM2gTkkdJAhzUpe7DcwmURdonwjdRdKitX-IhfgLRRSpLFUfqD9BquZjWnEERcPnHqobuTBDiTQL2vXoUZmURwXr4Kb3obEPaRz_vcZZSPCgHUv3TRNZ_WpXiX41HWBHWorkLpPaQpUCBVKlL1zkK7l0vpEEnEwD8JJ7Ba7xXVLaPzxBx1nj-ZCwUNR4rxf6yBvy3hvkFxEClEPlyP5yuuxXmYwua8"/> <link rel="stylesheet" media="all" href="/web/20231204172920cs_/https://www.nist.gov/sites/default/files/css/css_6prwlieMvitJqVLptJ59w_NxX2prM0abXhYVoH12prk.css?delta=1&language=en&theme=nist_www&include=eJx1kYGuwyAIRX_IVz_JUMuUzYoTXNe_X9utabPlJYbA4QZu0HNFe703rLPpwd-c8vKKPeXuKv-2yHM2gTkkdJAhzUpe7DcwmURdonwjdRdKitX-IhfgLRRSpLFUfqD9BquZjWnEERcPnHqobuTBDiTQL2vXoUZmURwXr4Kb3obEPaRz_vcZZSPCgHUv3TRNZ_WpXiX41HWBHWorkLpPaQpUCBVKlL1zkK7l0vpEEnEwD8JJ7Ba7xXVLaPzxBx1nj-ZCwUNR4rxf6yBvy3hvkFxEClEPlyP5yuuxXmYwua8"/> <link rel="stylesheet" media="print" href="/web/20231204172920cs_/https://www.nist.gov/sites/default/files/css/css_6MuKXqcH69mMwmOSjiD2G_c6UXIqUTZ1TRnur95k7Qk.css?delta=2&language=en&theme=nist_www&include=eJx1kYGuwyAIRX_IVz_JUMuUzYoTXNe_X9utabPlJYbA4QZu0HNFe703rLPpwd-c8vKKPeXuKv-2yHM2gTkkdJAhzUpe7DcwmURdonwjdRdKitX-IhfgLRRSpLFUfqD9BquZjWnEERcPnHqobuTBDiTQL2vXoUZmURwXr4Kb3obEPaRz_vcZZSPCgHUv3TRNZ_WpXiX41HWBHWorkLpPaQpUCBVKlL1zkK7l0vpEEnEwD8JJ7Ba7xXVLaPzxBx1nj-ZCwUNR4rxf6yBvy3hvkFxEClEPlyP5yuuxXmYwua8"/> <link rel="stylesheet" media="all" href="/web/20231204172920cs_/https://www.nist.gov/sites/default/files/css/css_zxDJPMpCfrT8NQEavjogRlrVmShwu9oesPd2F7606bk.css?delta=3&language=en&theme=nist_www&include=eJx1kYGuwyAIRX_IVz_JUMuUzYoTXNe_X9utabPlJYbA4QZu0HNFe703rLPpwd-c8vKKPeXuKv-2yHM2gTkkdJAhzUpe7DcwmURdonwjdRdKitX-IhfgLRRSpLFUfqD9BquZjWnEERcPnHqobuTBDiTQL2vXoUZmURwXr4Kb3obEPaRz_vcZZSPCgHUv3TRNZ_WpXiX41HWBHWorkLpPaQpUCBVKlL1zkK7l0vpEEnEwD8JJ7Ba7xXVLaPzxBx1nj-ZCwUNR4rxf6yBvy3hvkFxEClEPlyP5yuuxXmYwua8"/> <script src="/web/20231204172920js_/https://www.nist.gov/sites/default/files/js/js_3ssAdmvsW-btol8ydZT2eloQN8l11yuGacOobfI1-_0.js?scope=header&delta=0&language=en&theme=nist_www&include=eJx1kYGuwyAIRX_IVz_JUMuUzYoTXNe_X9utabPlJYbA4QZu0HNFe703rLPpwd-c8vKKPeXuKv-2yHM2gTkkdJAhzUpe7DcwmURdonwjdRdKitX-IhfgLRRSpLFUfqD9BquZjWnEERcPnHqobuTBDiTQL2vXoUZmURwXr4Kb3obEPaRz_vcZZSPCgHUv3TRNZ_WpXiX41HWBHWorkLpPaQpUCBVKlL1zkK7l0vpEEnEwD8JJ7Ba7xXVLaPzxBx1nj-ZCwUNR4rxf6yBvy3hvkFxEClEPlyP5yuuxXmYwua8"></script> </head> <body class="node-411896"> <a href="#main-content" class="visually-hidden focusable" data-elastic-exclude> Skip to main content </a> <div class="dialog-off-canvas-main-canvas" data-off-canvas-main-canvas> <!-- nist-index-ignore-start --> <section data-elastic-exclude class="usa-banner" aria-label="Official government website"> <div class="usa-accordion"> <header class="usa-banner__header"> <div class="usa-banner__inner"> <div class="grid-col-auto"> <img class="usa-banner__header-flag" src="/web/20231204172920im_/https://www.nist.gov/libraries/nist-component-library/dist/img/us_flag_small.png" alt="U.S. flag"> </div> <div class="grid-col-fill tablet:grid-col-auto"> <p class="usa-banner__header-text">An official website of the United States government</p> <p class="usa-banner__header-action" aria-hidden="true">Here’s how you know</p> </div> <button class="usa-accordion__button usa-banner__button" aria-expanded="false" aria-controls="gov-banner-default"> <span class="usa-banner__button-text">Here’s how you know</span> </button> </div> </header> <div class="usa-banner__content usa-accordion__content" id="gov-banner-default"> <div class="grid-row grid-gap-lg"> <div class="usa-banner__guidance tablet:grid-col-6"> <img class="usa-banner__icon usa-media-block__img" src="/web/20231204172920im_/https://www.nist.gov/libraries/nist-component-library/dist/img/icon-dot-gov.svg" role="img" alt="" aria-hidden="true"> <div class="usa-media-block__body"> <p> <strong>Official websites use .gov</strong> <br/> A <strong>.gov</strong> website belongs to an official government organization in the United States. </p> </div> </div> <div class="usa-banner__guidance tablet:grid-col-6"> <img class="usa-banner__icon usa-media-block__img" src="/web/20231204172920im_/https://www.nist.gov/libraries/nist-component-library/dist/img/icon-https.svg" role="img" alt="" aria-hidden="true"> <div class="usa-media-block__body"> <p> <strong>Secure .gov websites use HTTPS</strong> <br/> A <strong>lock</strong> ( <span class="icon-lock"> <svg xmlns="http://www.w3.org/2000/svg" width="52" height="64" viewbox="0 0 52 64" class="usa-banner__lock-image" role="img" aria-labelledby="banner-lock-title banner-lock-description" focusable="false"> <title id="banner-lock-title">Lock</title> <desc id="banner-lock-description">A locked padlock</desc><path fill="#000000" fill-rule="evenodd" d="M26 0c10.493 0 19 8.507 19 19v9h3a4 4 0 0 1 4 4v28a4 4 0 0 1-4 4H4a4 4 0 0 1-4-4V32a4 4 0 0 1 4-4h3v-9C7 8.507 15.507 0 26 0zm0 8c-5.979 0-10.843 4.77-10.996 10.712L15 19v9h22v-9c0-6.075-4.925-11-11-11z"/></svg> </span> ) or <strong>https://</strong> means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. </p> </div> </div> </div> </div> </div> </section> <!-- nist-index-ignore-end --> <div data-elastic-exclude> <!-- nist-index-ignore-start --> <div class="nist-print-header" style="display:none;"> <p class="nist-print-header__url">https://www.nist.gov/pml/owm</p> <img class="nist-print-header__logo" width="289" height="38" src="/web/20231204172920im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/nist_logo_sidestack.svg" alt="National Institute of Standards and Technology"/> </div> <div class="usa-overlay"></div> <header class="usa-header nist-header--www nist-header--minimal" role="banner"> <div class="usa-navbar"> <div class="usa-logo flex-fill"> <a href="/web/20231204172920/https://www.nist.gov/" title="National Institute of Standards and Technology" aria-label="Home"> <img src="/web/20231204172920im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/logo.svg" alt="National Institute of Standards and Technology" width="300px" height="80px"/> </a> </div> <div class="usa-header__right grid-row flex-auto"> <div class="grid-col-fill nist-header__search-group"> <form class="usa-search usa-search--small" accept-charset="UTF-8" action="/web/20231204172920/https://www.nist.gov/search" id="search_form" method="get"> <div role="search"> <label class="usa-sr-only" for="search-form">Search NIST</label> <input class="usa-input" id="search-form" type="search" name="s" placeholder="Search NIST" required="" maxlength="128"> <button class="usa-button" type="submit"><img src="/web/20231204172920im_/https://www.nist.gov/libraries/nist-component-library/dist/img/usa-icons-bg/search--white.svg" class="usa-search__submit-icon" alt="Search"></button> </div> </form> </div> <div class="grid-col-auto padding-left-1"> <button class="usa-menu-btn">Menu</button> </div> </div> </div> <nav aria-label="Primary navigation" class="usa-nav"> <div class="usa-nav__inner"> <button class="usa-nav__close">Close</button> <ul class="usa-nav__primary usa-accordion"> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-1"><span>Topics</span></button> <div id="primary_menu-1" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/topics" class="usa-nav__link">All Topics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/advanced-communications" class="usa-nav__link">Advanced communications</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/artificial-intelligence" class="usa-nav__link">Artificial intelligence</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/bioscience" class="usa-nav__link">Bioscience</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/buildings-construction" class="usa-nav__link">Buildings and construction</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/chemistry" class="usa-nav__link">Chemistry</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/climate" class="usa-nav__link">Climate</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/cybersecurity" class="usa-nav__link">Cybersecurity</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/electronics" class="usa-nav__link">Electronics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/energy" class="usa-nav__link">Energy</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/environment" class="usa-nav__link">Environment</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/fire" class="usa-nav__link">Fire</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/forensic-science" class="usa-nav__link">Forensic science</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/health" class="usa-nav__link">Health</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/information-technology" class="usa-nav__link">Information technology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/infrastructure" class="usa-nav__link">Infrastructure</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/manufacturing" class="usa-nav__link">Manufacturing</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/materials" class="usa-nav__link">Materials</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/mathematics-statistics" class="usa-nav__link">Mathematics and statistics</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/metrology" class="usa-nav__link">Metrology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/nanotechnology" class="usa-nav__link">Nanotechnology</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/neutron-research" class="usa-nav__link">Neutron research</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/performance-excellence" class="usa-nav__link">Performance excellence</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/physics" class="usa-nav__link">Physics</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/public-safety" class="usa-nav__link">Public safety</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/resilience" class="usa-nav__link">Resilience</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/standards" class="usa-nav__link">Standards</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/transportation" class="usa-nav__link">Transportation</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <a class="usa-nav__link" href="/web/20231204172920/https://www.nist.gov/publications">Publications</a> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-3"><span>Labs & Major Programs</span></button> <div id="primary_menu-3" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/labs-major-programs/laboratories" class="usa-nav__link">Laboratories</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231204172920/https://www.nist.gov/ctl" class="usa-nav__link">Communications Technology Laboratory</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/el" class="usa-nav__link">Engineering Laboratory</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/itl" class="usa-nav__link">Information Technology Laboratory</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/mml" class="usa-nav__link">Material Measurement Laboratory</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/pml" class="usa-nav__link">Physical Measurement Laboratory</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/labs-major-programs/user-facilities" class="usa-nav__link">User Facilities</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231204172920/https://www.nist.gov/ncnr" class="usa-nav__link">NIST Center for Neutron Research</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/cnst" class="usa-nav__link">CNST NanoFab</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/labs-major-programs/research-test-beds" class="usa-nav__link">Research Test Beds</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/laboratories/projects-programs" class="usa-nav__link">Research Projects</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/laboratories/tools-instruments" class="usa-nav__link">Tools & Instruments</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/labs-major-programs/major-programs" class="usa-nav__link">Major Programs</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231204172920/https://www.nist.gov/baldrige" class="usa-nav__link">Baldrige Performance Excellence Program</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/chips" class="usa-nav__link">CHIPS for America Initiative</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/mep" class="usa-nav__link">Manufacturing Extension Partnership (MEP)</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/oam" class="usa-nav__link">Office of Advanced Manufacturing</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/spo" class="usa-nav__link">Special Programs Office</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/tpo" class="usa-nav__link">Technology Partnerships Office</a> </li> </ul> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link usa-current" aria-expanded="false" aria-controls="primary_menu-4"><span>Services & Resources</span></button> <div id="primary_menu-4" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/services-resources/standards-and-measurements" class="usa-nav__link usa-current">Standards and Measurements</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231204172920/https://www.nist.gov/calibrations" class="usa-nav__link">Calibration Services</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/nvlap" class="usa-nav__link">Laboratory Accreditation (NVLAP)</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/nist-quality-system" class="usa-nav__link">Quality System</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/srm" class="usa-nav__link">Standard Reference Materials (SRMs)</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/standardsgov" class="usa-nav__link">Standards.gov</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/pml/time-and-frequency-division/time-services" class="usa-nav__link">Time Services</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/pml/owm" class="usa-nav__link usa-current">Office of Weights and Measures</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/services-resources/software" class="usa-nav__link">Software</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/data" class="usa-nav__link">Data</a> <ul class="usa-nav__submenu-list"> <li> <a href="https://web.archive.org/web/20231204172920/https://webbook.nist.gov/chemistry/" class="usa-nav__link">Chemistry WebBook</a> </li> <li> <a href="https://web.archive.org/web/20231204172920/https://nvd.nist.gov/" class="usa-nav__link">National Vulnerability Database</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/pml/productsservices/physical-reference-data" class="usa-nav__link">Physical Reference Data</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/srd" class="usa-nav__link">Standard Reference Data (SRD)</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/shop" class="usa-nav__link">Storefront</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/tpo" class="usa-nav__link">License & Patents</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="https://web.archive.org/web/20231204172920/https://csrc.nist.gov/" class="usa-nav__link">Computer Security Resource Center (CSRC)</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/nist-research-library" class="usa-nav__link">NIST Research Library</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-5"><span>News & Events</span></button> <div id="primary_menu-5" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/news-events/news" class="usa-nav__link">News</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/news-events/events" class="usa-nav__link">Events</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/blogs" class="usa-nav__link">Blogs</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/feature-stories" class="usa-nav__link">Feature Stories</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/awards" class="usa-nav__link">Awards</a> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/video-gallery" class="usa-nav__link">Video Gallery</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/image-gallery" class="usa-nav__link">Image Gallery</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/pao/media-contacts" class="usa-nav__link">Media Contacts</a> </li> </ul> </div> </div> </div> </li> <li class="usa-nav__primary-item"> <button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-6"><span>About NIST</span></button> <div id="primary_menu-6" class="usa-nav__submenu usa-megamenu"> <div class="grid-row"> <div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/about-nist" class="usa-nav__link">About Us</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/about-nist/contact-us" class="usa-nav__link">Contact Us</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/about-nist/visit" class="usa-nav__link">Visit</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/careers" class="usa-nav__link">Careers</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/director/nist-organization-structure" class="usa-nav__link">Our Organization</a> <ul class="usa-nav__submenu-list"> <li> <a href="/web/20231204172920/https://www.nist.gov/director" class="usa-nav__link">Office of the Director</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/director/nist-organization-structure/budget-planning" class="usa-nav__link">Budget & Planning</a> </li> </ul> </li> </ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list"> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/about-nist/work-nist" class="usa-nav__link">Work with NIST</a> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/history" class="usa-nav__link">History</a> <ul class="usa-nav__submenu-list"> <li> <a href="https://web.archive.org/web/20231204172920/http://nistdigitalarchives.contentdm.oclc.org/" class="usa-nav__link">NIST Digital Archives</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/nist-museum" class="usa-nav__link">NIST Museum</a> </li> <li> <a href="/web/20231204172920/https://www.nist.gov/nist-and-nobel" class="usa-nav__link">NIST and the Nobel</a> </li> </ul> </li> <li class="usa-nav__submenu-item"> <a href="/web/20231204172920/https://www.nist.gov/education" class="usa-nav__link">Educational Resources</a> </li> </ul> </div> </div> </div> </li> </ul> </div> </nav> </header> <!-- nist-index-ignore-end --> </div> <div class="grid-container"> <div data-drupal-messages-fallback class="hidden"></div> </div> <div id="block-nist-www-content" class="nist-block"> <section class="nist-page__content usa-section clearfix"> <a id="main-content" tabindex="-1"></a> <div class="nist-section-header nist-section-header--menu"> <div class="nist-section-header__top grid-container"> <a href="/web/20231204172920/https://www.nist.gov/pml">Physical Measurement Laboratory</a> </div> <div class="nist-section-header__sub"> <div class="nist-section-header__main grid-container"> <div class="grid-row"> <div class="nist-section-header__title tablet-lg:grid-col-4"> <h1 class="nist-page__title">Office of Weights and Measures</h1> </div> <div class="nist-section-header__desc tablet-lg:grid-col-8"> <div class="text-with-summary"> <p>OWM establishes uniformity, equity, SI use, and traceability in weights and measures by advancing national and international legal metrology standards, procedures, capabilities, and training.</p> </div> </div> </div> </div> </div> </div> <div class="grid-container margin-top-4"> <div class="grid-row grid-gap-6"> <aside class="nist-page__region nist-page__region--sidebar-first tablet-lg:grid-col-4 desktop-lg:grid-col-3"> <div> <!-- nist-index-ignore-start --> <div data-elastic-exclude="" class="nist-block"> <nav> <ul class="usa-sidenav usa-accordion "> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml" data-drupal-link-system-path="">Laboratory Homepage</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm" data-drupal-link-system-path="">Division Homepage</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/about-us" data-drupal-link-system-path="">About Us</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/faqs" data-drupal-link-system-path="">FAQs</a> </li> <li class="usa-sidenav__item usa-sidenav__item--parent"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/owm-products-and-services" data-drupal-link-system-path="">OWM Products and Services</a> <button class="usa-accordion__button" aria-expanded="false" aria-controls="menu-office-of-weights-and-measu-5"><span class="usa-sr-only">Expand or Collapse</span></button> <ul id="menu-office-of-weights-and-measu-5" class="usa-sidenav__sublist usa-accordion"> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/owm-products-and-services/publications-and-documentary-standards" data-drupal-link-system-path="">Publications and Documentary Standards</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/owm-products-and-services/learning-resources" data-drupal-link-system-path="">Learning Resources</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/owm-training-and-events" data-drupal-link-system-path="">Training Courses and Events</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/owm-products-and-services/newsletter-and-articles" data-drupal-link-system-path="">Newsletter and Articles</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/owm-products-and-services/us-national-working-groups" data-drupal-link-system-path="">U.S. National Working Groups</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/owm-products-and-services/owm-contacts-system" data-drupal-link-system-path="">OWM Contacts System</a> </li> </ul> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/owm-training-and-events" data-drupal-link-system-path="">OWM Training and Events</a> </li> <li class="usa-sidenav__item usa-sidenav__item--parent"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/programsgroups" data-drupal-link-system-path="">Programs/Groups</a> <button class="usa-accordion__button" aria-expanded="false" aria-controls="menu-office-of-weights-and-measu-7"><span class="usa-sr-only">Expand or Collapse</span></button> <ul id="menu-office-of-weights-and-measu-7" class="usa-sidenav__sublist usa-accordion"> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/international-legal-metrology" data-drupal-link-system-path="">International Legal Metrology</a> <button class="usa-accordion__button" aria-expanded="false" aria-controls="menu-office-of-weights-and-measu-7-1"><span class="usa-sr-only">Expand or Collapse</span></button> <ul id="menu-office-of-weights-and-measu-7-1" class="usa-sidenav__sublist usa-accordion"> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/international-legal-metrology/documentary-standards" data-drupal-link-system-path="">Documentary Standards</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/international-legal-metrology/glossary-acronyms" data-drupal-link-system-path="">Glossary of Acronyms</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/international-legal-metrology/ilmp-organizational-primer" data-drupal-link-system-path="">ILMP Organizational Primer</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/international-legal-metrology/oiml-resources" data-drupal-link-system-path="">OIML Resources</a> </li> </ul> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/laboratory-metrology" data-drupal-link-system-path="">Laboratory Metrology</a> <button class="usa-accordion__button" aria-expanded="false" aria-controls="menu-office-of-weights-and-measu-7-2"><span class="usa-sr-only">Expand or Collapse</span></button> <ul id="menu-office-of-weights-and-measu-7-2" class="usa-sidenav__sublist usa-accordion"> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/laboratory-metrology/calibration-procedures" data-drupal-link-system-path="">Calibration Procedures</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/laboratory-metrology/standard-operating-procedures" data-drupal-link-system-path="">Standard Operating Procedures</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/laboratory-metrology/good-laboratory-practices" data-drupal-link-system-path="">Good Laboratory Practices</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/laboratory-metrology/good-measurement-practices" data-drupal-link-system-path="">Good Measurement Practices</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/laboratory-metrology/proficiency-testing" data-drupal-link-system-path="">Proficiency Testing</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/laboratory-metrology/state-lab-program-resources" data-drupal-link-system-path="">State Lab Program Resources</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/laboratory-metrology/lab-metrology-training" data-drupal-link-system-path="">Lab Metrology Training</a> </li> </ul> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/metric-si" data-drupal-link-system-path="">Metric (SI)</a> <button class="usa-accordion__button" aria-expanded="false" aria-controls="menu-office-of-weights-and-measu-7-3"><span class="usa-sr-only">Expand or Collapse</span></button> <ul id="menu-office-of-weights-and-measu-7-3" class="usa-sidenav__sublist usa-accordion"> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/metric-si/us-metrication" data-drupal-link-system-path="">U.S. Metrication</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/metric-si/si-units" data-drupal-link-system-path="">SI Units</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/metric-si/understanding-metric" data-drupal-link-system-path="">Understanding Metric</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/metric-si/everyday-metric" data-drupal-link-system-path="">Everyday with Metric</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/metric-si/metric-kitchen" data-drupal-link-system-path="">Metric Kitchen</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/metric-si/si-education-training" data-drupal-link-system-path="">SI Education & Training</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/metric-si/unit-conversion" data-drupal-link-system-path="">Unit Conversion</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/metric-si/metric-policy" data-drupal-link-system-path="">Metric Policy</a> </li> </ul> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/national-legal-metrology" data-drupal-link-system-path="">National Legal Metrology</a> <button class="usa-accordion__button" aria-expanded="false" aria-controls="menu-office-of-weights-and-measu-7-4"><span class="usa-sr-only">Expand or Collapse</span></button> <ul id="menu-office-of-weights-and-measu-7-4" class="usa-sidenav__sublist usa-accordion"> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/laws-and-regulations/laws-and-regulations-resources" data-drupal-link-system-path="">Laws and Regulations Resources</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/laws-and-regulations/fuels-and-lubricants-subcommittee-fals" data-drupal-link-system-path="">Fuels and Lubricants Subcommittee (FALS)</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/owm-products-and-services/learning-resources" data-drupal-link-system-path="">Legal Devices Training Materials</a> </li> <li class="usa-sidenav__item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/pml/owm/laws-and-regulations/price-verification" data-drupal-link-system-path="">Price Verification</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/laws-and-regulations/precious-metals-conversion" data-drupal-link-system-path="">Precious Metals Conversion</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/news-events/events/2013/04/packaging-and-labeling" data-drupal-link-system-path="">Packaging and Labeling</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/owm-products-and-services/us-national-working-groups" data-drupal-link-system-path="">U.S. National Working Groups</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/laws-and-regulations/us-retail-pricing-laws-and-regulations" data-drupal-link-system-path="">U.S. Retail Pricing Laws and Regulations</a> </li> </ul> </li> </ul> </li> <li class="usa-sidenav__item usa-sidenav__item--parent"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/staff-directory" data-drupal-link-system-path="">Staff Directory</a> <button class="usa-accordion__button" aria-expanded="false" aria-controls="menu-office-of-weights-and-measu-8"><span class="usa-sr-only">Expand or Collapse</span></button> <ul id="menu-office-of-weights-and-measu-8" class="usa-sidenav__sublist usa-accordion"> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/staff-directory/federal-staff" data-drupal-link-system-path="">Federal Staff</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/staff-directory/associates-and-interns" data-drupal-link-system-path="">Associates and Interns</a> </li> <li class="usa-sidenav__item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/document/owm-organization-chart" data-drupal-link-system-path="">Organization Chart</a> </li> </ul> </li> <li class="usa-sidenav__item usa-sidenav__item--parent"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/external-resources-weights-and-measures" data-drupal-link-system-path="">External Resources for Weights and Measures</a> <button class="usa-accordion__button" aria-expanded="false" aria-controls="menu-office-of-weights-and-measu-9"><span class="usa-sr-only">Expand or Collapse</span></button> <ul id="menu-office-of-weights-and-measu-9" class="usa-sidenav__sublist usa-accordion"> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/external-resources-weights-and-measures/weights-and-measures-news" data-drupal-link-system-path="">Weights and Measures in the News</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/external-resources-weights-and-measures/state-weights-and-measures-directors" data-drupal-link-system-path="">State Weights and Measures Directors</a> </li> <li class="usa-sidenav__item"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/external-resources-weights-and-measures/state-metrology-laboratories" data-drupal-link-system-path="">State Metrology Laboratories</a> </li> <li class="usa-sidenav__item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/document/us-wm-and-metrologist-directory" data-drupal-link-system-path="">U.S. W&M and Metrologist Directory</a> </li> <li class="usa-sidenav__item"> <a href="https://web.archive.org/web/20231204172920/https://www.ncwm.com/" data-drupal-link-system-path="">National Conference on Weights and Measures (NCWM)</a> </li> <li class="usa-sidenav__item"> <a href="https://web.archive.org/web/20231204172920/https://www.ncwm.com/ntep-about" data-drupal-link-system-path="">National Type Evaluation Program (NTEP)</a> </li> </ul> </li> </ul> </nav> </div> <!-- nist-index-ignore-end --> <!-- nist-index-ignore-start --> <div class="views-element-container nist-block nist-block--org" data-elastic-exclude=""> <h2 class="nist-block__title">Groups</h2> <div><div class="js-view-dom-id-31d75272c698772e9ce9b85284bfb6f439dc0a62927c4c945ff86d5ba51c559b"> <div class="link-list"> <ul> <li><div class="views-field views-field-title-1"><span class="field-content"><a href="/web/20231204172920/https://www.nist.gov/pml/owm/international-legal-metrology" hreflang="en">International Legal Metrology</a></span></div></li> <li><div class="views-field views-field-title-1"><span class="field-content"><a href="/web/20231204172920/https://www.nist.gov/pml/owm/laboratory-metrology" hreflang="en">Laboratory Metrology</a></span></div></li> <li><div class="views-field views-field-title-1"><span class="field-content"><a href="/web/20231204172920/https://www.nist.gov/pml/owm/metric-si" hreflang="en">Metric (SI) Program</a></span></div></li> <li><div class="views-field views-field-title-1"><span class="field-content"><a href="/web/20231204172920/https://www.nist.gov/pml/owm/national-legal-metrology" hreflang="en">National Legal Metrology</a></span></div></li> </ul> </div> </div> </div> </div> <!-- nist-index-ignore-end --> </div> </aside> <div class="nist-page__region nist-page__region--content tablet-lg:grid-col-8 desktop-lg:grid-col-9"> <div class="nist-block"> <div class="paragraph paragraph--type--hero paragraph--view-mode--default"> <div class="nist-hero grid-row grid-gap-2"> <div class="nist-hero__item tablet:grid-col-4 "> <div class="nist-hero__item-inner"> <div class="nist-hero__image"> <a href="/web/20231204172920/https://www.nist.gov/publications/evolving-regulatory-landscape-commercial-electric-vehicle-fueling"> <picture> <source srcset="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/600w_x_360h/public/images/2023/08/30/Auto%20Population.jpeg.webp?itok=8rAb1PKR 1x, /web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/1200w_x_720h/public/images/2023/08/30/Auto%20Population.jpeg.webp?itok=4fZOpzdY 2x" media="(min-width: 480px)" type="image/webp" width="600" height="360"/> <source srcset="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/300w_x_180h/public/images/2023/08/30/Auto%20Population.jpeg.webp?itok=txaW47UC 1x, /web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/600w_x_360h/public/images/2023/08/30/Auto%20Population.jpeg.webp?itok=8rAb1PKR 2x" media="(min-width: 0px)" type="image/webp" width="300" height="180"/> <img loading="eager" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/600w_x_360h/public/images/2023/08/30/Auto%20Population.jpeg.jpg?itok=8rAb1PKR" width="600" height="360" alt="Evolving Regulatory Landscape for EV Charging" typeof="foaf:Image"/> </picture> </a> </div> <div class="nist-hero__caption"> <a href="/web/20231204172920/https://www.nist.gov/publications/evolving-regulatory-landscape-commercial-electric-vehicle-fueling"> <div class="text">Evolving Regulatory Landscape for EV Charging</div> </a> </div> </div> </div> <div class="nist-hero__item tablet:grid-col-4 "> <div class="nist-hero__item-inner"> <div class="nist-hero__image"> <a href="/web/20231204172920/https://www.nist.gov/programs-projects/nist-owm-ncwm-enduring-partnership-over-100-years"> <picture> <source srcset="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/600w_x_360h/public/images/2023/08/23/OWM%20NCWM%20Group%20Photo.png.webp?itok=p1QKdbCP 1x, /web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/1200w_x_720h/public/images/2023/08/23/OWM%20NCWM%20Group%20Photo.png.webp?itok=ceVkBc8K 2x" media="(min-width: 480px)" type="image/webp" width="600" height="360"/> <source srcset="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/300w_x_180h/public/images/2023/08/23/OWM%20NCWM%20Group%20Photo.png.webp?itok=LPsqjRPn 1x, /web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/600w_x_360h/public/images/2023/08/23/OWM%20NCWM%20Group%20Photo.png.webp?itok=p1QKdbCP 2x" media="(min-width: 0px)" type="image/webp" width="300" height="180"/> <img loading="eager" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/600w_x_360h/public/images/2023/08/23/OWM%20NCWM%20Group%20Photo.png.jpg?itok=p1QKdbCP" width="600" height="360" alt="group photo taken at NCWM 2023 Annual Meeting; Craig VanBuren, Don Onwiler, and Mahesh Albuquerque of NCWM, Laurie Locascio and Katrice Lippa of NIST, Gene Robertson of NCWM, David Sefcik" typeof="foaf:Image"/> </picture> </a> </div> <div class="nist-hero__caption"> <a href="/web/20231204172920/https://www.nist.gov/programs-projects/nist-owm-ncwm-enduring-partnership-over-100-years"> <div class="text">NIST OWM – NCWM: An Enduring Partnership for Over 100 Years</div> </a> </div> </div> </div> <div class="nist-hero__item tablet:grid-col-4 "> <div class="nist-hero__item-inner"> <div class="nist-hero__image"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/owm-products-and-services/learning-resources"> <picture> <source srcset="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/600w_x_360h/public/images/2023/05/17/e-learning.jpg.webp?itok=28U_yr8s 1x, /web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/1200w_x_720h/public/images/2023/05/17/e-learning.jpg.webp?itok=58KT7IDM 2x" media="(min-width: 480px)" type="image/webp" width="600" height="360"/> <source srcset="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/300w_x_180h/public/images/2023/05/17/e-learning.jpg.webp?itok=rL5JOjUG 1x, /web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/600w_x_360h/public/images/2023/05/17/e-learning.jpg.webp?itok=28U_yr8s 2x" media="(min-width: 0px)" type="image/webp" width="300" height="180"/> <img loading="eager" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/600w_x_360h/public/images/2023/05/17/e-learning.jpg.jpg?itok=28U_yr8s" width="600" height="360" alt="Finger tapping orange key on keyboard e-learning" typeof="foaf:Image"/> </picture> </a> </div> <div class="nist-hero__caption"> <a href="/web/20231204172920/https://www.nist.gov/pml/owm/owm-products-and-services/learning-resources"> <div class="text">OWM Learning Resources</div> </a> </div> </div> </div> </div> </div> <div class="nist-content-row nist-content-row--width-legible paragraph paragraph--type--text paragraph--view-mode--default"> <div class="nist-block text-long"><div class="OutlineElement Ltr SCXW216710491 BCX2"> <div class="OutlineElement Ltr SCXW115286206 BCX2"> <p>The NIST Office of Weights and Measures (OWM) works to ensure that consumers get what they pay for, and sellers get fair payment for the goods and services they sell, by promoting a uniform and technically sound system of weights and measures. This, in turn, promotes consumer confidence and helps ensure fair competition for U.S. commerce that spans from local business operations to a global scale.</p> <p>To learn more about OWM and its roles and responsibilities, click <a data-entity-substitution="canonical" data-entity-type="node" data-entity-uuid="59dcbc3d-d5dd-4535-bb40-c3935f4652b8" href="/web/20231204172920/https://www.nist.gov/pml/owm/about-us" title="About OWM">About Us</a>.</p> <div class="nist-callout"> <p><strong>Originally established in 1836 as the “Office of Construction of Standard Weights and Measures”, OWM remains the oldest office at NIST. For more information, see <a data-entity-substitution="canonical" data-entity-type="node" data-entity-uuid="fa1e8786-3546-4cbb-8083-e3d8ca00a4d7" href="/web/20231204172920/https://www.nist.gov/pml/owm/brief-history-owm" title="A Brief History of OWM">A Brief History of OWM</a>.</strong></p> </div> </div> </div> <figure class="align-center nist-image" data-link="https://www.surveymonkey.com/r/OWMWebsiteFeedback"><a href="https://web.archive.org/web/20231204172920/https://www.surveymonkey.com/r/OWMWebsiteFeedback"><img alt="We want your feedback isolated banner vector design" height="113" loading="lazy" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/220_x_220_limit/public/images/2023/06/15/Feedback.png?itok=y4xGlFsK" typeof="foaf:Image" width="220"/></a><figcaption class="nist-image__caption"><div class="nist-image__caption-content" data-caption-editable="true"> </div> </figcaption></figure><p> </p></div> </div> <div class="paragraph paragraph--type--dynamic-content-list-ou paragraph--view-mode--default"> <div class="nist-block "> <h2 class="nist-block__title"> <div class="string">Events</div> </h2> <div class="viewsreference"><div class="views-element-container"><div class="js-view-dom-id-f0f1973627cb0d70520d929acd3f377b488a82d95c1896fe4095a70c8dac006e"> <div> <article about="/news-events/events/2023/12/5896-nist-handbook-130-examination-procedure-price-verification-wm" class="nist-teaser"> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/news-events/events/2023/12/5896-nist-handbook-130-examination-procedure-price-verification-wm"><span>5896 NIST Handbook 130 - Examination Procedure for Price Verification (W&M Measures officials only)</span> </a></h3> <div class="nist-teaser__date"> <div class="smartdate">Tue, Dec 12 2023, 11:00am - 1:30pm EST</div> </div> </header> <div class="nist-teaser__content"> <div class="text-with-summary"> This 2.5 hour webinar will provide inspectors with an understanding and knowledge of the NIST Handbook 130 Examination </div> </div> </div> </article> </div> <div> <article about="/news-events/events/2023/12/5892-nist-handbook-130-examination-procedure-price-verification-wm" class="nist-teaser"> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/news-events/events/2023/12/5892-nist-handbook-130-examination-procedure-price-verification-wm"><span>5892 NIST Handbook 130 - Examination Procedure for Price Verification (W&M Measures officials only)</span> </a></h3> <div class="nist-teaser__date"> <div class="smartdate">Thu, Dec 14 2023, 11:00am - 1:30pm EST</div> </div> </header> <div class="nist-teaser__content"> <div class="text-with-summary"> This 2.5 hour webinar will provide inspectors with an understanding and knowledge of the NIST Handbook 130 Examination </div> </div> </div> </article> </div> <div> <article about="/news-events/events/2023/12/5897-nist-handbook-130-examination-procedure-price-verification-wm" class="nist-teaser"> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/news-events/events/2023/12/5897-nist-handbook-130-examination-procedure-price-verification-wm"><span>5897 NIST Handbook 130 - Examination Procedure for Price Verification (W&M Measures officials only)</span> </a></h3> <div class="nist-teaser__date"> <div class="smartdate">Tue, Dec 19 2023, 11:00am - 1:30pm EST</div> </div> </header> <div class="nist-teaser__content"> <div class="text-with-summary"> This 2.5 hour webinar will provide inspectors with an understanding and knowledge of the NIST Handbook 130 Examination </div> </div> </div> </article> </div> <div> <article about="/news-events/events/2024/01/5858-fundamentals-metrology" class="nist-teaser"> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/news-events/events/2024/01/5858-fundamentals-metrology"><span>5858 Fundamentals of Metrology</span> </a></h3> <div class="nist-teaser__date"> <div class="smartdate">Mon, Jan 29 - Fri, Feb 2 2024</div> </div> </header> <div class="nist-teaser__content"> <div class="text-with-summary"> The 5-day Fundamentals of Metrology seminar is an intensive course that introduces participants to the concepts of </div> </div> </div> </article> </div> <footer> <div class="link-list"><a href="/web/20231204172920/https://www.nist.gov/news-events/upcoming-events/org/6436">View All Events</a></div> </footer> </div> </div> </div> </div> </div> <div class="paragraph paragraph--type--dynamic-content-list-ou paragraph--view-mode--default"> <div class="nist-block "> <h2 class="nist-block__title"> <div class="string">Projects and Programs</div> </h2> <div class="viewsreference"><div class="views-element-container"><div class="js-view-dom-id-054fa61662738806c504b2355067e536c7e2aa42785d0060299127cb347cf93a"> <div> <article about="/programs-projects/coriolis-mass-flow-meters-field-test-standards" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231204172920/https://www.nist.gov/programs-projects/coriolis-mass-flow-meters-field-test-standards" hreflang="en"><img loading="lazy" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2023/09/28/Jan%20Testing%20Device%20Thumbnail.png?itok=kbWS2igu" width="77" height="100" alt="Jan Konijnenburg Testing Device Thumbnail" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/programs-projects/coriolis-mass-flow-meters-field-test-standards"><span>Coriolis Mass Flow Meters as Field Test Standards</span> </a></h3> <div class="nist-teaser__type"> <div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div> </div> </header> <div class="nist-teaser__content"> <div class="text-long"> Commercial metering systems are ubiquitous in the commercial marketplace (to dispense liquified products, from gas and water to food products and agricultural </div> </div> </div> </article> </div> <div> <article about="/programs-projects/electric-vehicle-supply-equipment-evse-test-instrumentation-guidance-documentation" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231204172920/https://www.nist.gov/programs-projects/electric-vehicle-supply-equipment-evse-test-instrumentation-guidance-documentation" hreflang="en"><img loading="lazy" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2023/08/14/Parked%20Electric%20Vehicles%20Charging.png?itok=BKDoNKKi" width="100" height="61" alt=" Public parking along the street with charging points for electric vehicles" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/programs-projects/electric-vehicle-supply-equipment-evse-test-instrumentation-guidance-documentation"><span>Electric Vehicle Supply Equipment (EVSE) Test Instrumentation: Guidance Documentation</span> </a></h3> <div class="nist-teaser__type"> <div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div> </div> </header> <div class="nist-teaser__content"> <div class="text-long"> The NIST Office of Weights and Measures (OWM) will begin work on developing a guideline document assessing methods for establishing traceability to primary SI </div> </div> </div> </article> </div> <div> <article about="/programs-projects/national-metrology-systems-framework-global-trade" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231204172920/https://www.nist.gov/programs-projects/national-metrology-systems-framework-global-trade" hreflang="en"><img loading="lazy" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2023/08/14/World%20Flags%20International%20Business%20Globe_100811325.jpeg?itok=MHdiovEr" width="100" height="83" alt="World Flags International Business Globe" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/programs-projects/national-metrology-systems-framework-global-trade"><span>National Metrology Systems: A Framework for Global Trade</span> </a></h3> <div class="nist-teaser__type"> <div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div> </div> </header> <div class="nist-teaser__content"> <div class="text-long"> It’s an old phrase, but the world keeps getting smaller every day! This is especially true when it comes to the global marketplace and our reliance on one </div> </div> </div> </article> </div> <div> <article about="/programs-projects/nist-owm-ncwm-enduring-partnership-over-100-years" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231204172920/https://www.nist.gov/programs-projects/nist-owm-ncwm-enduring-partnership-over-100-years" hreflang="en"><img loading="lazy" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2023/08/23/OWM%20NCWM%20Group%20Photo.png?itok=Toq2DIV1" width="100" height="69" alt="group photo taken at NCWM 2023 Annual Meeting; Craig VanBuren, Don Onwiler, and Mahesh Albuquerque of NCWM, Laurie Locascio and Katrice Lippa of NIST, Gene Robertson of NCWM, David Sefcik" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/programs-projects/nist-owm-ncwm-enduring-partnership-over-100-years"><span>NIST OWM – NCWM: An Enduring Partnership for Over 100 Years</span> </a></h3> <div class="nist-teaser__type"> <div class="nist-badge display-inline-block margin-y-1 nist-badge--blue boolean">Ongoing</div> </div> </header> <div class="nist-teaser__content"> <div class="text-long"> On August 1, 2023, the National Institute of Standards and Technology ( NIST ) and the National Conference on Weights and Measures ( NCWM ) signed a new </div> </div> </div> </article> </div> <footer> <div class="link-list"><a href="/web/20231204172920/https://www.nist.gov/laboratories/projects-programs/org/6436">View All Projects/Programs</a></div> </footer> </div> </div> </div> </div> </div> <div class="paragraph paragraph--type--dynamic-content-list-ou paragraph--view-mode--default"> <div class="nist-block "> <h2 class="nist-block__title"> <div class="string">Newsletter Articles and Updates</div> </h2> <div class="viewsreference"><div class="views-element-container"><div class="js-view-dom-id-8208cb08d4937922a94b802539eead014cb7f99ac8910c764957322bec74b785"> <div> <article about="/news-events/news/2023/09/2023-nist-internship-reflections" typeof="schema:Article" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231204172920/https://www.nist.gov/news-events/news/2023/09/2023-nist-internship-reflections" hreflang="en"><img loading="lazy" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2023/09/29/OWM%20Summer%20Interns-2023.png?itok=8-PzVtqK" width="100" height="100" alt="OWM summer interns" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/news-events/news/2023/09/2023-nist-internship-reflections"><span property="schema:name">2023 NIST Internship Reflections</span> </a></h3> <div class="nist-teaser__date"> <div class="daterange"><time datetime="2023-09-28T12:00:00Z">September 28, 2023</time> </div> </div> </header> <div class="nist-teaser__content"> <div property="schema:text" class="text-with-summary"> During the summer of 2023, the NIST Physical Measurement Laboratory’s ( PML ) Office of Weights and Measures ( OWM ) hosted four undergraduate students who were </div> </div> </div> </article> </div> <div> <article about="/news-events/news/2023/09/what-true-meaning-scale-division-d-versus-verification-scale-division-e" typeof="schema:Article" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231204172920/https://www.nist.gov/news-events/news/2023/09/what-true-meaning-scale-division-d-versus-verification-scale-division-e" hreflang="en"><img loading="lazy" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2023/09/28/Thumb%20tag%20picture%20edited.png?itok=9_XbLLh1" width="100" height="45" alt="Scale" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/news-events/news/2023/09/what-true-meaning-scale-division-d-versus-verification-scale-division-e"><span property="schema:name">What is the true meaning of a “scale division” (d) versus a “verification scale division” (e)</span> </a></h3> <div class="nist-teaser__date"> <div class="daterange"><time datetime="2023-09-28T12:00:00Z">September 28, 2023</time> </div> </div> </header> <div class="nist-teaser__content"> <div property="schema:text" class="text-with-summary"> Introduction If you are a state weights and measures official, scale manufacturer, or any other stakeholder dealing with scales used for commercial transactions </div> </div> </div> </article> </div> <div> <article about="/news-events/news/2023/09/nist-sp2200-03-evolving-regulatory-landscape-commercial-electric-vehicle" typeof="schema:Article" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231204172920/https://www.nist.gov/news-events/news/2023/09/nist-sp2200-03-evolving-regulatory-landscape-commercial-electric-vehicle" hreflang="en"><img loading="lazy" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2023/08/30/Auto%20Population.jpeg?itok=GX0mhnMj" width="100" height="60" alt="Evolving Regulatory Landscape for EV Charging" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/news-events/news/2023/09/nist-sp2200-03-evolving-regulatory-landscape-commercial-electric-vehicle"><span property="schema:name">NIST SP2200-03: An Evolving Regulatory Landscape for Commercial Electric Vehicle Fueling</span> </a></h3> <div class="nist-teaser__date"> <div class="daterange"><time datetime="2023-09-28T12:00:00Z">September 28, 2023</time> </div> </div> </header> <div class="nist-teaser__content"> <div property="schema:text" class="text-with-summary"> NIST OWM has just published the latest installment of its NIST Special Publication 2200 series on Legal Metrology , NIST SP 2200-03 An Evolving Regulatory </div> </div> </div> </article> </div> <div> <article about="/news-events/news/2023/09/metric-week-2023-seven-days-si-fun" typeof="schema:Article" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231204172920/https://www.nist.gov/news-events/news/2023/09/metric-week-2023-seven-days-si-fun" hreflang="en"><img loading="lazy" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2023/09/19/2023-Metric%20Week_0.png?itok=9tf27gSN" width="100" height="100" alt="Graphic with dates of 2023 Metric Week" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/news-events/news/2023/09/metric-week-2023-seven-days-si-fun"><span property="schema:name">Metric Week 2023: Seven Days of SI Fun</span> </a></h3> <div class="nist-teaser__date"> <div class="daterange"><time datetime="2023-09-20T12:00:00Z">September 20, 2023</time> </div> </div> </header> <div class="nist-teaser__content"> <div property="schema:text" class="text-with-summary"> National Metric Week (October 8 to 14, 2023) is an opportunity to underscore the usefulness of metric system measurements, formally known as the International </div> </div> </div> </article> </div> <footer> <div class="link-list"><a href="/web/20231204172920/https://www.nist.gov/news-events/news-updates/org/6436">View All News and Updates</a></div> </footer> </div> </div> </div> </div> </div> <div class="paragraph paragraph--type--dynamic-content-list-ou paragraph--view-mode--default"> <div class="nist-block "> <h2 class="nist-block__title"> <div class="string">Awards</div> </h2> <div class="viewsreference"><div class="views-element-container"><div class="js-view-dom-id-0e36b15ef98dbcaf47de757bc16be11be40c7ccf9a2738b3cac01cf9337e7e08"> <div> <article about="/awards/2023-ncwm-outstanding-contributions-award-david-sefcik" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231204172920/https://www.nist.gov/awards/2023-ncwm-outstanding-contributions-award-david-sefcik" hreflang="en"><img loading="lazy" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2023/08/17/David-NCWM_0.png?itok=qWNMkRqz" width="100" height="77" alt="David Sefcik (center) accepting his award from NCWM Chair-elect Gene Robertson (at the podium), NCWM Chair Mahesh Albuquerque (left) and NIST Director Laurie Locascio (right)." typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/awards/2023-ncwm-outstanding-contributions-award-david-sefcik"><span>2023 NCWM Outstanding Contributions Award - David Sefcik</span> </a></h3> </header> <div class="nist-teaser__content"> <div class="text-long"> David Sefcik of the NIST OWM received the 2023 NCWM Outstanding Contributions Award for his service as a co-organizer of the 2022 NCWM-NIST </div> </div> </div> </article> </div> <div> <article about="/awards/2023-best-review-award-published-2022-clay-davis-goncalo-gouveia-christina-jones-katrice" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231204172920/https://www.nist.gov/awards/2023-best-review-award-published-2022-clay-davis-goncalo-gouveia-christina-jones-katrice" hreflang="en"><img loading="lazy" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2023/06/24/Metabolomics%20Cover%20Artwork.JPG?itok=gBfC_CUQ" width="100" height="100" alt="Word collage (reference materials, QC tools, repeatability, compatibility, reproducibility, etc. over top of small jar" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/awards/2023-best-review-award-published-2022-clay-davis-goncalo-gouveia-christina-jones-katrice"><span>2023 - Best Review Award Published in 2022---Clay Davis, Goncalo Gouveia, Christina Jones, Katrice Lippa, and Tracey Schock</span> </a></h3> </header> <div class="nist-teaser__content"> <div class="text-long"> " Reference Materials for MS-based Untargeted Metabolomics and Lipidomics: A Review by the Metabolomics Quality Assurance and Quality </div> </div> </div> </article> </div> <div> <article about="/awards/elizabeth-j-benham-recognized-ieee-standards-association" class="nist-teaser"> <div class="nist-teaser__image"> <div class="entity-reference"> <a href="/web/20231204172920/https://www.nist.gov/awards/elizabeth-j-benham-recognized-ieee-standards-association" hreflang="en"><img loading="lazy" src="/web/20231204172920im_/https://www.nist.gov/sites/default/files/styles/thumbnail/public/images/2021/04/07/Elizabeth%20Benham%202021-03.jpg?itok=7FfNmdfA" width="80" height="100" alt="Staff Photo Elizabeth Benham" typeof="foaf:Image"/> </a> </div> </div> <div class="nist-teaser__content-wrapper"> <header> <h3 class="nist-teaser__title"><a href="/web/20231204172920/https://www.nist.gov/awards/elizabeth-j-benham-recognized-ieee-standards-association"><span>Elizabeth J. Benham Recognized by the IEEE Standards Association</span> </a></h3> </header> <div class="nist-teaser__content"> <div class="text-long"> The IEEE Standards Association is an organization focused on advancing global technologies through the Institute of Electrical and </div> </div> </div> </article> </div> <footer> <div class="link-list"><a href="/web/20231204172920/https://www.nist.gov/awards/org/6436">View All Awards</a></div> </footer> </div> </div> </div> </div> </div> </div> </div> </div> </div> <div class="grid-container"> <div class="nist-page__region nist-page__region--content-bottom"> <div class="nist-block nist-block--contact"> <h2 class="nist-block__title">Contacts</h2> <div class="nist-contact"> <h3 class="nist-contact__heading">General Inquiries:</h3> <ul class="nist-contact__items"> <li class="nist-contact__item"> <div class="nist-contact__name"> General Information - OWM </div> <div> <a href="https://web.archive.org/web/20231204172920/mailto:owm@nist.gov">owm@nist.gov</a> </div> <div> </div> </li> </ul> </div> <div class="nist-contact"> <h3 class="nist-contact__heading">Training Inquiries</h3> <ul class="nist-contact__items"> <li class="nist-contact__item"> <div class="nist-contact__name"> Yvonne Branden </div> <div> <a href="https://web.archive.org/web/20231204172920/mailto:yvonne.branden@nist.gov">yvonne.branden@nist.gov</a> </div> <div> </div> </li> </ul> </div> <div class="nist-contact"> <h3 class="nist-contact__heading">Website Inquiries:</h3> <ul class="nist-contact__items"> <li class="nist-contact__item"> <div class="nist-contact__name"> Yvonne Branden </div> <div> <a href="https://web.archive.org/web/20231204172920/mailto:yvonne.branden@nist.gov">yvonne.branden@nist.gov</a> </div> <div> </div> </li> </ul> </div> </div> </div> </div> </section> </div> <div data-elastic-exclude> <!-- nist-index-ignore-start --> <footer class="nist-footer padding-bottom-4"> <div class="grid-container nist-footer__info"> <div class="grid-row"> <div class="tablet:grid-col-6"> <div class="nist-footer__logo"> <a href="/web/20231204172920/https://www.nist.gov/" title="National Institute of Standards and Technology" rel="home"> <img class="nist-footer__logo-img" src="/web/20231204172920im_/https://www.nist.gov/libraries/nist-component-library/dist/img/logo/NIST-Logo-Brand-White.svg" alt="National Institute of Standards and Technology logo" width="300px" height="42px"/> </a> </div> <div class="nist-footer__contact"> <h3 class="nist-footer__contact-heading">HEADQUARTERS</h3> <address> 100 Bureau Drive<br> Gaithersburg, MD 20899<br> <a href="https://web.archive.org/web/20231204172920/tel:301-975-2000">301-975-2000</a> </address> <p> <a href="https://web.archive.org/web/20231204172920/mailto:do-webmaster@nist.gov">Webmaster</a> | <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/about-nist/contact-us">Contact Us</a> | <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/visit">Our Other Offices</a> </p> </div> </div> <div class="tablet:grid-col-6"> <div class="nist-footer__social-links"> <a class="nist-social nist-social--twitter-white" href="https://web.archive.org/web/20231204172920/https://twitter.com/NIST"> <span>Twitter</span> </a> <a class="nist-social nist-social--facebook-white" href="https://web.archive.org/web/20231204172920/https://www.facebook.com/NIST"> <span>Facebook</span> </a> <a class="nist-social nist-social--linkedin-white" href="https://web.archive.org/web/20231204172920/https://www.linkedin.com/company/nist"> <span>LinkedIn</span> </a> <a class="nist-social nist-social--instagram-white" href="https://web.archive.org/web/20231204172920/https://www.instagram.com/nist/"> <span>Instagram</span> </a> <a class="nist-social nist-social--youtube-white" href="https://web.archive.org/web/20231204172920/https://www.youtube.com/NIST"> <span>YouTube</span> </a> <a class="nist-social nist-social--giphy-white" href="https://web.archive.org/web/20231204172920/https://giphy.com/nist"> <span>Giphy</span> </a> <a class="nist-social nist-social--rss-white" href="https://web.archive.org/web/20231204172920/https://www.nist.gov/news-events/nist-rss-feeds"> <span>RSS Feed</span> </a> <a class="nist-social nist-social--envelope-white" href="https://web.archive.org/web/20231204172920/https://public.govdelivery.com/accounts/USNIST/subscriber/new"> <span>Mailing List</span> </a> </div> <div class="nist-footer__feedback"> How are we doing? <a class="usa-button" rel="nofollow" href="/web/20231204172920/https://www.nist.gov/form/nist-gov-feedback?destination=/pml/owm" title="Provide feedback">Feedback</a> </div> </div> </div> </div> <div class="grid-container"> <div class="nist-footer__nav" role="navigation"> <ul> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/privacy-policy">Site Privacy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/oism/accessibility">Accessibility</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/privacy">Privacy Program</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/oism/copyrights">Copyrights</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/https://www.commerce.gov/vulnerability-disclosure-policy">Vulnerability Disclosure</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/no-fear-act-policy">No Fear Act Policy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/office-director/freedom-information-act">FOIA</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/environmental-policy-statement">Environmental Policy</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/summary-report-scientific-integrity">Scientific Integrity</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/https://www.nist.gov/nist-information-quality-standards">Information Quality Standards</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/https://www.commerce.gov/">Commerce.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/http://www.science.gov/">Science.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/http://www.usa.gov/">USA.gov</a> </li> <li class="nist-footer__menu-item"> <a href="https://web.archive.org/web/20231204172920/https://vote.gov/">Vote.gov</a> </li> </ul> </div> </div> </footer> <!-- nist-index-ignore-end --> </div> </div> <script type="application/json" data-drupal-selector="drupal-settings-json">{"path":{"baseUrl":"\/","scriptPath":null,"pathPrefix":"","currentPath":"node\/411896","currentPathIsAdmin":false,"isFront":false,"currentLanguage":"en"},"pluralDelimiter":"\u0003","suppressDeprecationErrors":true,"back_to_top":{"back_to_top_button_trigger":100,"back_to_top_prevent_on_mobile":false,"back_to_top_prevent_in_admin":true,"back_to_top_button_type":"image","back_to_top_button_text":"Back to top"},"google_analytics":{"account":"G-HEQ0YF2VYL","trackOutbound":true,"trackMailto":true,"trackTel":true,"trackDownload":true,"trackDownloadExtensions":"7z|aac|arc|arj|asf|asx|avi|bin|bsh|c|csv|doc(x|m)?|dot(x|m)?|dw(fx|g|gd)|dxf|eps|epub|exe|f(90)|flv|gif|gz|gzip|hqx|jar|jpe?g|js|m1v|mp(2|3|4|e?g)|mobi|mov(ie)?|msi|msp|pdf|phps|pl|png|ppt(x|m)?|pot(x|m)?|pps(x|m)?|ppam|sld(x|m)?|thmx|qtm?|ra(m|r)?|rfa|rtf|rvt|sch|sea|sit|swf|tar|tgz|tif|txt|txz|wav|wma|wmv|wpd|wrl|xls(x|m|b)?|xlt(x|m)|xlam|xml|xsd|z|zip"},"nist_search":{"clickTracking":"search-report-click","isDebug":false,"clickTrackEnabled":true,"message":"NIST Search in debug mode. Check the browsers network inspector for Click Track reporting results..."},"data":{"extlink":{"extTarget":false,"extTargetNoOverride":false,"extNofollow":false,"extNoreferrer":false,"extFollowNoOverride":false,"extClass":"ext","extLabel":"(link is external)","extImgClass":false,"extSubdomains":true,"extExclude":"\\.gov\\\/|\\.mil\\\/|\\manufacturingusa\\.com\\\/","extInclude":"","extCssExclude":"","extCssExplicit":"","extAlert":true,"extAlertText":"Thank you for visiting NIST. We hope your visit was informative. We have provided a link to this site because it has information that may be of interest to our users. NIST does not necessarily endorse the views expressed or the facts presented on this site. Further, NIST does not endorse any commercial products that may be advertised or available on this site. Click OK to be directed to your link.","mailtoClass":"0","mailtoLabel":"(link sends email)","extUseFontAwesome":false,"extIconPlacement":"append","extFaLinkClasses":"fa fa-external-link","extFaMailtoClasses":"fa fa-envelope-o","whitelistedDomains":[]}},"user":{"uid":0,"permissionsHash":"2f77e4dcfce20728ac491170886da836c10b580f9bdfeb9c9e729fe4958834d5"}}</script> <script src="/web/20231204172920js_/https://www.nist.gov/sites/default/files/js/js_wWC32cBD9qab55wFkKWKvOdi_p-P8cBjregEiEdV1z4.js?scope=footer&delta=0&language=en&theme=nist_www&include=eJx1kYGuwyAIRX_IVz_JUMuUzYoTXNe_X9utabPlJYbA4QZu0HNFe703rLPpwd-c8vKKPeXuKv-2yHM2gTkkdJAhzUpe7DcwmURdonwjdRdKitX-IhfgLRRSpLFUfqD9BquZjWnEERcPnHqobuTBDiTQL2vXoUZmURwXr4Kb3obEPaRz_vcZZSPCgHUv3TRNZ_WpXiX41HWBHWorkLpPaQpUCBVKlL1zkK7l0vpEEnEwD8JJ7Ba7xXVLaPzxBx1nj-ZCwUNR4rxf6yBvy3hvkFxEClEPlyP5yuuxXmYwua8"></script> <script src="https://web.archive.org/web/20231204172920js_/https://siteimproveanalytics.com/js/siteanalyze_6017546.js" async></script> <script src="/web/20231204172920js_/https://www.nist.gov/sites/default/files/js/js_5ryNUs6GxBdloDjzmRgzoVauqZxQeUM7_K9e9QHtDzs.js?scope=footer&delta=2&language=en&theme=nist_www&include=eJx1kYGuwyAIRX_IVz_JUMuUzYoTXNe_X9utabPlJYbA4QZu0HNFe703rLPpwd-c8vKKPeXuKv-2yHM2gTkkdJAhzUpe7DcwmURdonwjdRdKitX-IhfgLRRSpLFUfqD9BquZjWnEERcPnHqobuTBDiTQL2vXoUZmURwXr4Kb3obEPaRz_vcZZSPCgHUv3TRNZ_WpXiX41HWBHWorkLpPaQpUCBVKlL1zkK7l0vpEEnEwD8JJ7Ba7xXVLaPzxBx1nj-ZCwUNR4rxf6yBvy3hvkFxEClEPlyP5yuuxXmYwua8"></script> <script type="text/javascript">window.NREUM||(NREUM={});NREUM.info={"beacon":"gov-bam.nr-data.net","licenseKey":"37b7ccb661","applicationID":"1089704227","transactionName":"YFxUN0sADEdYVkBaClkWdwBNCA1aFkVVVABoWlcAUQQ=","queueTime":4,"applicationTime":45,"atts":"TBtXQQMaH0k=","errorBeacon":"gov-bam.nr-data.net","agent":""}</script></body> </html> <!-- FILE ARCHIVED ON 17:29:20 Dec 04, 2023 AND RETRIEVED FROM THE INTERNET ARCHIVE ON 07:53:59 Nov 26, 2024. JAVASCRIPT APPENDED BY WAYBACK MACHINE, COPYRIGHT INTERNET ARCHIVE. ALL OTHER CONTENT MAY ALSO BE PROTECTED BY COPYRIGHT (17 U.S.C. SECTION 108(a)(3)). --> <!-- playback timings (ms): captures_list: 0.608 exclusion.robots: 0.038 exclusion.robots.policy: 0.027 esindex: 0.011 cdx.remote: 62.796 LoadShardBlock: 223.924 (3) PetaboxLoader3.datanode: 89.058 (4) PetaboxLoader3.resolve: 232.51 (3) load_resource: 137.877 -->