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href="https://web-static.archive.org/_static/css/iconochive.css?v=3PDvdIFv" />  <meta http-equiv="X-UA-Compatible" content="IE=8"/> <title>BIPM - calibrations</title> <meta name="description" content="Calibration services"> <script language="javascript" src="/web/20200527212700js_/https://www.bipm.org/utils/onLoad.js"> </script> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//web.archive.org/web/20200527212700/https://www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-38070491-1', 'auto'); ga('send', 'pageview'); </script> <script src="/web/20200527212700js_/https://www.bipm.org/utils/jquery/jquery-1.10.2.min.js"></script> <script 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width="180"></td><td width="530"></td><td width="270"></td><td width="10"></td></tr> <tr height="90"> <td width="10"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pix.gif" width="10" height="90"></td> <td width="180" valign="center" align="left"><a href="/web/20200527212700/https://www.bipm.org/en/about-us/" title="BIPM home page"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/logoBIPM-RB.jpg" border="0"></a></td> <td width="530" valign="center" align="center" class="intro">    the intergovernmental organization through which Member States act together<br>      on matters related to measurement science and measurement standards.</td> <td width="270" align="center" valign="top"> <script language="javascript"> function ActionForm(f) { f.q.style.background = "white"; } </script> <form name="search" action="https://web.archive.org/web/20200527212700/https://search.bipm.org/bipm/en/C="> <table width="180" align="right" valign="top" border="0"> <tr height="50"> <td valign="bottom" class="intro">Search facility: <input onclick="ActionForm(this.form)" style="vertical-align: middle;background-image:url(/web/20200527212700im_/https://www.bipm.org/utils/en/img/bipm_portal.gif); background-repeat:no-repeat; background-position:center right;" type="text" name="q" size="25" maxlength="50"> <input type="hidden" name="action" value="s"> <input type="hidden" name="setcontext" value=""> </td> <td height="25" colspan="2" width="50" valign="bottom" align="left"><input type="image" src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/exalead.gif" border="0"></td> </tr> </table> </form> <br> <br> <img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pix.gif" width="270" height="15" border="0"> <nobr><a href="/web/20200527212700/https://www.bipm.org/en/about-us/"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/home.png" border="0"></a> | <a class="navigation" 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href="/web/20200527212700/https://www.bipm.org/en/worldwide-metrology/cgpm/" target="_self">The General Conference (CGPM)</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/committees/cipm/" target="_self">The International Committee (CIPM)</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/committees/cc/" target="_self">CIPM Consultative Committees (CCs)</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/worldwide-metrology/national/" target="_self">National Metrology Institutes (NMIs)</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/worldwide-metrology/regional/" target="_self">Regional Metrology Organizations (RMOs)</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/committees/jc/" target="_self">Joint Committees</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/worldwide-metrology/liaisons/" target="_self">BIPM liaison work</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/cbkt/" target="_self">BIPM Capacity Building & Knowledge Transfer Programme</a></li> <li><a href="https://web.archive.org/web/20200527212700/http://www.worldmetrologyday.org/" target="_blank">World Metrology Day</a></li> </ul> </li> <li><a href="/web/20200527212700/https://www.bipm.org/en/cipm-mra/" target="_self"> International equivalence</a> <ul> <li><a href="/web/20200527212700/https://www.bipm.org/en/cipm-mra/" target="_self">What is the CIPM MRA?</a></li> <li><a href="https://web.archive.org/web/20200527212700/https://www.bipm.org/kcdb" target="_self">CIPM MRA database <img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img2/logo_kcdb_pt.gif"></a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/cipm-mra/participation/" target="_self">Participating laboratories</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/cipm-mra/cipm-mra-documents/" target="_self">CIPM MRA documents</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/cipm-mra/approval-process.html" target="_self">CMC approval process</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/cipm-mra/logo/" target="_self">Use of the CIPM MRA logo</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/committees/jc/jcrb/" target="_self">JCRB: Joint Committee of the RMOs and the BIPM</a></li> </ul> </li> <li><a href="/web/20200527212700/https://www.bipm.org/en/measurement-units/" target="_self"> SI units</a> <ul> <li><a href="/web/20200527212700/https://www.bipm.org/en/measurement-units/" target="_self">The International System of Units (SI)</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/si-brochure/" target="_self">SI Brochure</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/si-brochure/appendix1.html" target="_self">Decisions of the CGPM and the CIPM</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/mises-en-pratique/" target="_self">How to realize the definitions in practice</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/measurement-units/base-units.html" target="_self">Unit definitions</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/measurement-units/prefixes.html" target="_self">SI prefixes</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/si-download-area/" target="_self">Revised SI: Download area</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/measurement-units/history-si/" target="_self">Brief history of the SI</a></li> </ul> </li> <li><a href="/web/20200527212700/https://www.bipm.org/en/bipm-services/" target="_self"> Services</a> <ul> <li><a href="/web/20200527212700/https://www.bipm.org/en/bipm-services/comparisons/" target="_self">Comparisons piloted by the BIPM</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/bipm-services/calibrations/" target="_self">Calibration and measurement services</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/bipm/tai/" target="_self">Timescales</a></li> <li><a href="https://web.archive.org/web/20200527212700/https://www.bipm.org/kcdb" target="_self"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img2/logo_kcdb_pt.gif" alt="KCDB" vspace="2"></a></li> <li><a href="https://web.archive.org/web/20200527212700/https://www.bipm.org/jctlm/" target="_self"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img2/logo_jctlm_pt.gif" alt="JCTLM" vspace="2"></a></li> <li><a href="https://web.archive.org/web/20200527212700/http://imrr.bipm.org/" target="_self"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img2/logo_imrr_pt.gif" alt="IMRR" vspace="2"></a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/si-brochure/" target="_self">SI Brochure</a></li> <li><a href="https://web.archive.org/web/20200527212700/http://iopscience.iop.org/0026-1394/" target="metrologia"><i>Metrologia</i></a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/conference-centre/" target="_self">Meetings</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/mises-en-pratique/standard-frequencies.html" target="_self">Recommended values of standard frequencies</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/bipm/ionizing/radionuclides/sir/" target="_self">International Reference System (SIR)</a></li> </ul> </li> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/" target="_self"> Publications</a> <ul> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/si-brochure/" target="_self">SI Brochure</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/mises-en-pratique/" target="_self"><i>Mises en pratique</i></a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/directors-report/" target="_self">Annual Director's Report</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/committees/cipm/publications-cipm.html#ra" target="_self">Financial Report</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/committees/cipm/publications-cipm.html#no" target="_self">Notification of Contributions</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/" target="_self">Official proceedings</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/worldwide-metrology/cgpm/resolutions.html" target="_self">Resolutions of the General Conference</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/open-literature/" target="_self">Scientific output</a></li> <li><a href="https://web.archive.org/web/20200527212700/http://iopscience.iop.org/0026-1394/" target="metrologia"><i>Metrologia</i></a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/guides/" target="_self">Guides in Metrology</a></li> </ul> </li> <li><a href="/web/20200527212700/https://www.bipm.org/en/conference-centre/diary/" target="_self"> Meetings</a> <ul> <li><a href="/web/20200527212700/https://www.bipm.org/en/conference-centre/diary/" target="_self">List of meetings</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/conference-centre/" target="_self">BIPM Conference Centre</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/conference-centre/directions/" target="_self">How to get to the BIPM</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/cgpm-2018/" target="_self">General Conference (CGPM)</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/committees/cipm/" target="_self">International Committee (CIPM)</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/committees/cc/" target="_self">Consultative Committees and Working Groups</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/conference-centre/bipm-workshops/" target="_self">BIPM Workshops</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/conference-centre/other-events/" target="_self">Other BIPM events</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/publications/" target="_self">Meeting reports</a></li> <li><a href="/web/20200527212700/https://www.bipm.org/en/worldwide-metrology/metrology-events.html" target="_self">External events</a></li> </ul> </li> </ul> </div> </td> </tr> </table>   <table width="1000" height="25" border="0" cellspacing="0" cellpadding="0"> <tr height="25"> <td height="25" bgcolor="#DBE3EB"> <table width="100%" border="0" cellspacing="0" cellpadding="0"> <tr> <td width="10"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pix.gif" width="10"></td> <td class="navigation" width="100%">> You are here: <a href="/web/20200527212700/https://www.bipm.org/en/bipm/" class="navigation">BIPM work programme</a> > <a href="/web/20200527212700/https://www.bipm.org/en/bipm/mass/" class="navigation">Mass</a> > calibrations </td> <td width="10"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pix.gif" width="10"></td> </tr> </table> </td> </tr> </table>   <center> <table width="1000" border="0" cellspacing="0" cellpadding="0"> <tr> <td width="10" height="50"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pix.gif" width="10" height="50"></td> <td align="left" width="100%" height="50" background="/web/20200527212700im_/https://www.bipm.org/utils/common/img/cadre_trait.gif"> <table width="100%" border="0" background="/web/20200527212700im_/https://www.bipm.org/en/bipm/mass/calibrations_mass/"> <tr> <td align="left" class="GrosTitre"><div name="exalead-titre">Calibration services</div></td> </tr> </table> </td> <td width="10" height="50"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pix.gif" width="10" height="50"></td> </tr> </table> </center>  <script> $(function() { $( "#tabs" ).tabs(); $( "#accordion" ).accordion({ heightStyle: "content", }); $( "#accordionG" ).accordion({ heightStyle: "content", }); $( "#accordionD" ).accordion({ heightStyle: "content", }); }); </script>  <table width="1000" border="0" cellspacing="0" cellpadding="0"> <tr valign="top"> <td width="10"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pix.gif" width="10"></td> <td width="100%" id="body"> <div id="tabs"> <ul> <li><a href="#overview">Overview</a></li> <li><a href="#link"><a href="/web/20200527212700/https://www.bipm.org/en/bipm-services/calibrations/cms_m.html">BIPM mass calibration and measurement services</a></a></li> <li><a href="#link"><a href="/web/20200527212700/https://www.bipm.org/utils/en/pdf/BIPM-services-mass.pdf">Summary of recent services per Member State <img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/chart4.gif" border="0"></a></a></li> <li><a href="#link"><a href="https://web.archive.org/web/20200527212700/http://www.bipm.org/en/bipm/mass/calibrations_mass/certificates.html">Calibration certificates</a></a></li> <li><a href="#link"><a href="/web/20200527212700/https://www.bipm.org/utils/en/pdf/Density_of_standards.pdf">Density of standards <img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pdf.gif" border="0"></a></a></li> <li><a href="#link"><a href="/web/20200527212700/https://www.bipm.org/utils/en/pdf/calib_proto.pdf">Request the calibration of a national prototype <img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pdf.gif" border="0"></a></a></li> <li><a href="#link"><a href="/web/20200527212700/https://www.bipm.org/utils/en/pdf/calib_inox.pdf">Request the calibration of a 1 kg standard in stainless steel <img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pdf.gif" border="0"></a></a></li> <li><a href="#back"><a href=".."><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/blue_arrow_14px.jpg">   </a></a></li> </ul> <div id="overview"> <ul class="txt12pt"> <p>The primary role of the BIPM's activity in Mass is to provide traceability to the kilogram</a>.</p> <p>Calibrations of Pt-Ir prototypes and mass standards in stainless steel are carried out each year during the periods <b>March to May</b> and <b>September to November</b>.</p> <p style="color:#FF0000" ;><b>The BIPM is the pilot laboratory for the first key comparison of kg realizations, CCM.M-K8.2019. Therefore the mass calibration service will be temporarily suspended during the first half of 2020.</b></p> <br> <script> $(function() { $("#accordion2").accordion({ heightStyle: "content", }); }); </script> <div id="accordion2"> <h3>1 kg prototypes in Pt-Ir</h3> <div> <ul> <p>The BIPM offers a calibration service for 1 kg national prototypes in Pt-Ir. This service is available free of charge to Member States. The Physical Metrology Department maintains a number of prototypes and other standards in Pt-Ir. A subset of these are used as working standards to calibrate national prototypes upon request. The remainder are used for quality control. Since <nobr>20 May 2019</nobr> the kilogram is defined with respect to the fixed numerical value of the Planck constant. Before the completion of the first key comparison of realization experiments, the traceability will be based on the known relationship between the mass of the International Prototype of the Kilogram (IPK) and the Planck constant. The combined standard uncertainty is about <nobr>0.012 mg.</nobr> This uncertainty is dominated by the standard uncertainty of <nobr>0.010 mg</nobr> of the mass of the IPK with respect to the Planck constant. The standard uncertainty of the prototype under calibration with respect to the IPK is about <nobr>0.005 mg.</nobr></p> <p>The BIPM also fabricates Pt-Ir prototypes for Member States upon request.</p> <li> <a href="/web/20200527212700/https://www.bipm.org/utils/en/pdf/calib_proto.pdf" class="introGras">Request the calibration of a national prototype <img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pdf.gif" border="0"></a></li> <br> </ul> </div> <h3>1 kg mass standards in stainless steel</h3> <div> <ul> <p>The BIPM offers a calibration service for <nobr>1 kg</nobr> standards in stainless steel. This service is available free of charge to NMIs of Member States. The volume of the standard can be determined by <a href="/web/20200527212700/https://www.bipm.org/utils/en/pdf/Density_of_standards.pdf" class="introgras">hydrostatic weighing</a> at the BIPM if this parameter is unknown (typical combined standard uncertainty obtained at the BIPM is <nobr>0.44 mm<sup>3</sup></nobr> at the reference temperature of <nobr>20.0 °C).</nobr> However, the volumetric thermal expansion near room temperature must be supplied by the NMI or the manufacturer of the standard. Since <nobr>20 May 2019</nobr> the kilogram is defined with respect to the fixed numerical value of the Planck constant. Before the completion of the first key comparison of realization experiments, the traceability will be based on the known relationship between the mass of the International Prototype of the Kilogram (IPK) and the Planck constant. The combined standard uncertainty is about <nobr>0.012 mg.</nobr> This uncertainty is dominated by the standard uncertainty of <nobr>0.010 mg</nobr> of the mass of the IPK with respect to the Planck constant. The standard uncertainty of the stainless steel standard under calibration with respect to the IPK is about <nobr>0.006 mg.</nobr> </p> <li><a href="/web/20200527212700/https://www.bipm.org/utils/en/pdf/calib_inox.pdf" class="introGras"> Request the calibration of a 1 kg standard in stainless steel <img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pdf.gif" border="0"></a></li> <br> </ul> </div> </div> </ul> </div> </div> </td> <td width="10" valign="top"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pix.gif" width="10" height="5"></td> </tr> <tr height="5"> <td colspan="5" width="100%" color="purple"><img src="/web/20200527212700im_/https://www.bipm.org/utils/common/img/pix.gif" width="100%" height="5" alt=""></td> </tr> </table>   <table width="100%" bgcolor="#D3B657"> <tr> <td width="15%"></td> <td width="1000"> <table width="1000" border="0" cellspacing="0" cellpadding="0"> <tr> <td nowrap width="100%"> <style media="all" 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