Acoustic Techniques in Fluid Metrology

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nist-page__region--content-top"> <div class="nist-block"> <a class="usa-button usa-button--accent-cool" href="/web/20230320132423/https://www.nist.gov/laboratories/projects-programs">PROJECTS/PROGRAMS</a> </div> <div class="nist-block"> <h1 class="nist-page__title">Acoustic Techniques in Fluid Metrology</h1> </div> <div class="nist-block">  <div data-elastic-exclude class="nist-block nist-social__wrapper"> <h2 class="nist-social__title">Share</h2> <div class="social-media-sharing"> <div class="nist-social__wrapper--share"> <div> <a target="_blank" rel="noopener" href="https://web.archive.org/web/20230320132423/https://www.facebook.com/share.php?u=https://www.nist.gov/programs-projects/acoustic-techniques-fluid-metrology" title="Facebook" class="nist-social nist-social--facebook-gray"> <span>Facebook</span> </a> </div> <div> <a target="_blank" rel="noopener" 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<span>Email</span> </a> </div> </div> </div> </div>  </div> </div> </div> <div class="grid-container margin-top-4"> <div class="grid-row grid-gap-6"> <div class="nist-page__region nist-page__region--content tablet-lg:grid-col-8"> <div class="nist-block gray-box"> <div class="text-long"> <h2>Summary</h2> <p>The Fluid Metrology Group leads the world in designing and using gas-filled acoustic resonators for measuring the thermodynamic temperature <em>T</em>, the Boltzmann constant <em>k</em>B, and the thermophysical properties (<em>e.g.</em> heat capacity, shear viscosity, acoustic and density virial coefficients) of semiconductor process gases and environmentally benign heat transfer fluids (<em>e.g.</em> refrigerants). Now, we are using our expertise to solve problems related to greenhouse gases.</p> </div> </div> <div class="nist-block"> <h2 class="nist-block__title">Description</h2> <div class="text-with-summary"> <div class="margin-left-4 margin-bottom-2 align-right"> <figure class="nist-image--lightbox nist-image" data-lightbox="https://www.nist.gov/sites/default/files/styles/2800_x_2800_limit/public/images/2016/12/14/acoustic_thermometer_a.jpg?itok=vHTyepLl" data-media-id="127421"> <img src="/web/20230320132423im_/https://www.nist.gov/sites/default/files/styles/480_x_480_limit/public/images/2016/12/14/acoustic_thermometer_a.jpg?itok=KJz4q4-y" width="350" height="390" alt="The NIST Acoustic Thermometer" loading="lazy" typeof="foaf:Image"/> <figcaption class="nist-image__caption"> <div data-caption-editable="true" class="nist-image__caption-content"> <p>Figure 1. Three-liter spherical cavity resonator used to measure the thermodynamic temperature from 273 K to 552 K.</p> </div> </figcaption> </figure> </div> <ol><li>In collaboration with NIST's Chemical Sciences Division, we use photoacoustic resonators <ol start="1"><li>for continuous monitoring of the CO2 concentration in ambient air from a tall building rooftop; (see Fig. 2) [<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/photoacoustic-spectrometer-accurate-continuous-measurements-atmospheric-carbon-dioxide">1</a>]</li> <li>for measuring the optical properties of particles (e.g. soot) in air that affect the energy balance of the earth; [<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/direct-measurements-mass-specific-optical-cross-sections-single-component-aerosol" title="jg radney et al, direct measurements of mass-specific optical cross sections of single-component aerosol mixtures, analytical chemistry, volume 85, pages 8319 to 8325, 2013">2</a>]</li> <li>to develop a hybrid cavity-ringdown/photoacoustic spectrometer for measuring the abundance of C-14 in samples of CO2 to verify product origin.</li> </ol></li> <li>In collaboration with China's National Institute of Metrology, we use cylindrical acoustic resonators to re-determine the Boltzmann constant with fractional uncertainty of 3脳10-6 from measurements of the speed of sound in argon. [<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/improved-determination-boltzmann-constant-using-single-fixed-length-cylindrical-cavity" title="h lin et al, improved determination of the boltzmann constant using a single, fixed-length cylindrical cavity, metrologia, volume 50, pages 417 to 432, 2013">3a</a>, <a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/test-virtual-cylindrical-acoustic-resonator-determining-boltzmann-constant" title="xj feng et al, test of a virtual cylindrical acoustic resonator for determining the boltzmann constant, metrologia, in press 2015">3b</a>]</li> <li> <figure class="align-right nist-image"><img alt="Photoacoustic resonator" height="170" loading="lazy" src="/web/20230320132423im_/https://www.nist.gov/sites/default/files/styles/220_x_220_limit/public/images/2016/09/13/pas_resonator_sm.jpg?itok=tPF_OHAD" typeof="foaf:Image" width="140"><figcaption class="nist-image__caption"><div class="nist-image__caption-content" data-caption-editable="true"> Figure 2. Photoacoustic resonator for optical absorption measurements in gases and aerosols. </div> </figcaption></figure>Design a <a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/pml/sensor-science/fluid-metrology/long-wavelength-acoustic-flowmeter" title="measuring complex gas flows with a long-wavelength acoustic flow meter">Long-Wavelength Acoustic Flow Meter</a> to measure the flux of carbon dioxide in the stack of a coal-burning power plant to facilitate a carbon tax or cap-and-trade regulations.</li> </ol> </div> </div> <div class="nist-block"> <h2 class="nist-block__title">Major Accomplishments</h2> <div class="text-long"><ol><li>Measured the thermodynamic temperature using cavities acting as simultaneous acoustic and microwave resonators from <ol start="1"><li>77K to 273 K using a <a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/acoustic-thermometry-new-results-273-k-77-k-and-progress-towards-4-k" title="l pitre et al, acoustic thermometry: new results from 273 k to 77 k and progress towards 4 k, metrologia, volume 43, pages 142 to 162, 2006">quasi-spherical cavity resonator</a></li> <li>271 K to 552 K using a <a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/acoustic-thermometry-results-271-k-552-k" title="rc ripple et al, acoustic thermometry results from 271 k to 552 k, tempmeko, volume 28, pages 1789 to 1799, 2007">spherical cavity resonator</a></li> <li>documented best-in-the-world techniques of <a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/acoustic-gas-thermometry-0" title="mr moldover et al, acoustic gas thermometry, metrologia v51, pp r1-r19 (2014)">acoustic thermometry</a></li> <li>"weigh" the <a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/weighing-gas-microwave-and-acoustic-resonances" title="ka gillis et al, 'weighing' a gas with microwave and acoustic resonances, metrologia v52, pp 337-352 (2015)">quantity of gas</a> in a large tank with large temperature gradients</li> </ol></li> </ol>聽<p> <figure class="align-center nist-image--lightbox nist-image" data-lightbox="https://www.nist.gov/sites/default/files/styles/2800_x_2800_limit/public/images/2016/09/13/tank-with-insulation-2.jpg?itok=vj-CyE-3" data-media-id="104061"><img alt="tank with insulation" height="266" loading="lazy" src="/web/20230320132423im_/https://www.nist.gov/sites/default/files/styles/480_x_480_limit/public/images/2016/09/13/tank-with-insulation-2.jpg?itok=Edfuao2G" typeof="foaf:Image" width="480"><figcaption class="nist-image__caption"><div class="nist-image__caption-content" data-caption-editable="true"> Figure 3. Acoustic resonances "weighed" the gas in this 300 liter tank while 13 K temperature differences were present. This is a model for a 30 m3 tank that will be used to calibrate flow meters. </div> </figcaption></figure></p> <ol start="2"><li> <figure class="align-center nist-image"><img alt="Resonator for measuring the bulk viscosity in xenon" height="152" loading="lazy" src="/web/20230320132423im_/https://www.nist.gov/sites/default/files/styles/220_x_220_limit/public/images/2016/09/13/bvx_resonator_sm.jpg?itok=WExQsPfb" typeof="foaf:Image" width="140"><figcaption class="nist-image__caption"><div class="nist-image__caption-content" data-caption-editable="true"> Figure 4. Hybrid cylindrical-Helmholtz resonator to measure speed of sound and 2nd viscosity over 27:1 frequency range. </div> </figcaption></figure>Designed cavity resonators (and associated ducts and transducers) for measuring the thermodynamic temperature from 4 K to 1350 K with fractional uncertainties as small as 3脳10-6.[<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/acoustic-gas-thermometry-0" title="mr moldover et al, acoustic gas thermometry, metrologia, volume 51, pages r1 to r19, 2014">4</a>,<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/microwave-measurements-gas-thermometry-copper-point" title="xj feng et al, microwave measurements for gas thermometry up to the copper point, metrologia, volume 50, pages 219 to 226, 2013">5</a>,<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/room-temperature-acoustic-transducers-high-temperature-thermometry" title="dc ripple et al, room temperature acoustic transducers for high-temperature thermometry, temperature: its measurement and control in science and industry, vol. 8, ed. c. meyer, aip conference proc., melville, ny, 2012">6</a>,<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/perturbations-ducts-modes-acoustic-thermometers" title="ka gillis et al, perturbations from ducts on the modes of acoustic thermometers, j res nist, volume 114, pages 263 to 285, 2009">7</a>,<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/second-order-boundary-corrections-radial-acoustic-eigenvalues-spherical-cavity" title="ka gillis, second-order boundary corrections to the radial acoustic eigenvalues for a spherical cavity, metrologia, volume 49, pages l21 to l24, 2012">8</a>]</li> <li>Developed a self-calibrating photoacoustic spectrometer with a calculable cell constant (Fig. 2) for absolute measurements of optical absorption in gases and aerosols.[<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/standard-photoacoustic-spectrometer-model-and-validation-using-o2-band-spectra" title="ka gillis et al, standard photoacoustic spectrometer: model and validation using o2 a-band spectra, rev sci instruments, volume 81, article 064902, pages 1 to 13, 2010">9</a>,<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/amplification-optical-absorption-cross-section-aerosols-soot-nonabsorbing-coating" title="p bueno et al, amplification of the optical absorption cross section for aerosols of soot with a nonabsorbing coating from photoacoustic measurements, aerosol science and technology, volume 45, pages 1217 to 1230, 2011">10</a>]</li> <li>Measured the 2nd viscosity (also called "bulk" or "dilation" viscosity) of xenon near its liquid-vapor critical point near 16聽掳C and 5.8聽MPa using a novel hybrid acoustic resonator (Fig 4). [<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/bulk-viscosity-thermoacoustic-boundary-layers-and-adsorption-near-critical-point" title="ka gillis et al, bulk viscosity, thermoacoustic boundary layers, and adsorption near the critical point, phys rev lett, volume 97, article 104502, pages 1 to 4, 2006">11</a>]</li> <li>Measured the viscosities and viscosity virial coefficients of semiconductor process gases [<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/pml/sensor-science/fluid-metrology/database-thermophysical-properties-gases-used-semiconductor">NIST Standard Reference Database 134 - SEMIPROP</a>] and environmentally-benign refrigerants [<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/viscosity-seven-gases-measured-greenspan-viscometer" title="jj hurly et al, the viscosity of seven gases measured with a greenspan viscometer, int j thermophys, volume 24, pages 1441 to 1474, 2003">12</a>, <span class="spamspan"><span class="u">keith.gillis</span> [at] <span class="d">nist.gov</span><span class="h"> (subject: reprint%20request, body: please%20send%20me%20a%20pdf%20of%20the%20article%3A%20af%20estrada-alexanders%20and%20jj%20hurly%2C%20kinematic%20viscosity%20and%20speed%20of%20sound%20in%20gaseous%20co%2C%20co2%2C%20sif4%2C%20sf6%2C%20c4f8%2C%20and%20nh3%20from%20220%20k%20to%20375%20k%20and%20pressures%20up%20to%203.4%20mpa%2C%20j%20chem%20thermodynamics%2C%20volume%2040%2C%20pages%20193%20to%20202%2C%202008) </span><span class="t"> (13)</span><span class="e">title="af estrada-alexanders and jj hurly, kinematic viscosity and speed of sound in gaseous co, co2, sif4, sf6, c4f8, and nh3 from 220 k to 375 k and pressures up to 3.4 mpa, j chem thermodynamics, volume 40, pages 193 to 202, 2008"</span></span>, <a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/srd/refprop">REFPROP</a>] using a novel acoustic viscometer.</li> <li> <figure class="align-right nist-image"><img alt="Cylindrical cavity resonator with acoustic waveguides" height="216" loading="lazy" src="/web/20230320132423im_/https://www.nist.gov/sites/default/files/styles/220_x_220_limit/public/images/2016/09/13/cylindrical_resonator_with_waveguides_sm.jpg?itok=BsQaeDns" typeof="foaf:Image" width="140"><figcaption class="nist-image__caption"><div class="nist-image__caption-content" data-caption-editable="true"> Figure 6. Cylindrical cavity (14 cm long; 6.5 cm diameter) resonator used to measure the speed of sound in semiconductor process gases and refrigerants. </div> </figcaption></figure><figure class="align-right nist-image"><img alt="Greenspan acoustic viscometer" height="96" loading="lazy" src="/web/20230320132423im_/https://www.nist.gov/sites/default/files/styles/220_x_220_limit/public/images/2016/09/13/acoustic_viscometer_sm.jpg?itok=gsDq5kf4" typeof="foaf:Image" width="140"><figcaption class="nist-image__caption"><div class="nist-image__caption-content" data-caption-editable="true"> Figure 5. Greenspan acoustic viscometer for gases. </div> </figcaption></figure>Designed acoustic resonators equipped with acoustic waveguides and remote transducers, and used them to measure the thermodynamic properties of industrial gases under extreme conditions. [<a href="https://web.archive.org/web/20230320132423/https://www.nist.gov/publications/room-temperature-acoustic-transducers-high-temperature-thermometry" title="dc ripple et al, room temperature acoustic transducers for high-temperature thermometry, temperature: its measurement and control in science and industry, vol. 8, ed. c. meyer, aip conference proc., melville, ny, 2012">6</a>,<span class="spamspan"><span class="u">keith.gillis</span> [at] <span class="d">nist.gov</span><span class="h"> (subject: reprint%20request, body: please%20send%20me%20a%20pdf%20of%20the%20article%3A%20accurate%20acoustic%20measurements%20in%20gases%20under%20difficult%20conditions%2C%20ka%20gillis%20et%20al%2C%20rev%20sci%20instruments%2C%20volume%2062%2C%20pages%202213%20to%202217%2C%201991) </span><span class="t"> (14)</span><span class="e">title="ka gillis et al, accurate acoustic measurements in gases under difficult conditions, rev sci instruments, volume 62, pages 2213 to 2217, 1991"</span></span>]</li> </ol></div> </div> <div class="nist-block">  <div data-elastic-exclude="" class="nist-tags"> <a href="/web/20230320132423/https://www.nist.gov/topic-terms/chemical-engineering-and-processing" hreflang="en">Chemical engineering and processing</a>, <a href="/web/20230320132423/https://www.nist.gov/topic-terms/metrology" hreflang="en">Metrology</a>, <a href="/web/20230320132423/https://www.nist.gov/topic-terms/flow-metrology-and-rheology" hreflang="en">Flow metrology and rheology</a> and <a href="/web/20230320132423/https://www.nist.gov/topic-terms/thermodynamics" hreflang="en">Thermodynamics</a></div>  </div> </div> <aside class="nist-page__region nist-page__region--sidebar-second tablet-lg:grid-col-4"> <div>  <div class="views-element-container nist-block nist-block--org" data-elastic-exclude=""> <h2 class="nist-block__title">Organizations</h2> <div><div class="js-view-dom-id-3c36e28fa02ff12130e081727be872a148e2d8384430385fdd8c5c8063ab9bda"> <div 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