Comparison of an ultrasonic interferometer manometer and a static expansion system using a capacitance diaphragm gauge

Mohan, Pardeep; Sharma, D. R.; Gupta, A. C.

doi:10.1088/0026-1394/33/2/6

Cited by 8 publications

(7 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this equation, R and R K are the pressure and temperature ratios as defined previously (eqs. (1) and (2)), x is a variable proportional to pressure (p 2 ) that may depend on temperature (T 1 , T 2 ) and θ is another step-like function, necessary related but not identical to Θ in eq. (3).…”

Section: Empirical Treatments Of Thermal Transpirationmentioning

confidence: 99%

“…The different schemes express the pressure ratio R = p 1 /p 2 (1) between two volume elements at two different temperatures T 1 < T 2 and connected by a tube of diameter d as a function of the pressure in the sensor p 2 over a pressure range that varies from viscous to molecular flow regimes. By convention [e.g.…”

Section: Introductionmentioning

confidence: 99%

“…CDG instruments, which are temperature regulated at above ambient (typically at T 2 = 318.15 K) thus find widespread applications in many areas of metrology and are widely recognised and used as low to medium vacuum transfer standards [e.g. 1,2].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

On the gas dependence of thermal transpiration and a critical appraisal of correction methods for capacitive diaphragm gauges

Daudé¹,

Elandaloussi²,

Janssen³

2014

Vacuum

View full text Add to dashboard Cite

Paris 06, UMR 7092, LPMAA (now LERMA2), Tour 32-33 2 e ét., 4 pl. Jussieu, 75005 Paris, France b CNRS, UMR 7092, LPMAA (now LERMA2), Tour 32-33 2 e ét., 4 pl. Jussieu, 75005 Paris, France Thermal transpiration effects are commonly encountered in low pressure measurements with capacitance diaphragm gauges. They arise from the temperature difference between the measurement volume and the temperature stabilised manometer. Several approaches have been proposed to correct for the pressure difference, but surface and geometric effects usually require that the correction is determined for each gas type and gauge individually. Common (semi) empirical corrections are based on studies of atoms or small molecules. We present a simple calibration method for diaphragm gauges and compare transpiration corrections for argon and styrene at pressures above 1 Pa. We find that characteristic pressures at which the pressure difference reaches half its maximum value, are compatible with the universal scaling p 1/2 = 2η · v th /d, thus essentially depending on gas viscosity η, thermal molecular speed v th and gauge tubing diameter d. This contradicts current recommendations based on the Takaishi and Sensui formula, which show an unphysical scaling with molecular size. Our results support the Miller or Šetina equations where the pressure dependency is basically determined by the Knudsen number. The use of these two schemes is therefore recommended, especially when thermal transpiration has to be predicted for new molecules. Implications for investigations on large polyatomics are discussed.

show abstract

Section: Empirical Treatments Of Thermal Transpirationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

On the gas dependence of thermal transpiration and a critical appraisal of correction methods for capacitive diaphragm gauges

Daudé¹,

Elandaloussi²,

Janssen³

2014

Vacuum

View full text Add to dashboard Cite

show abstract

“…2 in the present part 2. The details of the system have been discussed in a number of references [6][7][8][9][10][11]. Here the gas is trapped in the smaller volume v s , between valves 4 and 5, at a known pressure p s .…”

Section: Generation Of Pressures In the Range 01 To 10 Pamentioning

confidence: 99%

Static expansion primary vacuum standard — Part 2: Characterization of two spinning rotor gauges

Mohan

Kumar

2009

MAPAN

View full text Add to dashboard Cite

The Part 1 of this paper discussed the determination of the volume ratio of the Static Expansion Primary Vacuum Standard (SES). Part 2 of the paper discusses in detail the use of the SES thus characterized for generating primary pressures. This standard has been used to calibrate Spinning Rotor Gauges (SRGs) at a number of pressures in the range 0.1 Pa to 1 Pa in steps of 0.1 Pa. The Gauge Coefficient at each of these pressures, defined as equal to the ratio of the indicated pressure to the true pressure is then plotted against the true pressure. The resulting straight line plot has a negative slope and its intercept equals the gauge coefficient. Two SRGs, NPL-0 and NPL-2 thus calibrated are used (i) as a device for measuring the pressure rise in the flowmeter of the National Physical Laboratory, India (NPLI) orifice flow system and (ii) as a secondary standard for the calibration of the user gauges.

show abstract

“…liquid column manometers (LCM), dead weight testers (DWT), quartz resonators (QR), pressure dial gauges (PDG), resistance / capacitance / inductance type pressure transducers / transmitters (PT). LCM and DWT measure pressure based on primary principle having well defined mathematical expression / model for measurand and are categorized as primary / reference instruments [3][4]. The evaluation of measurement uncertainty for such instruments is readily evaluated and can be characterized by the estimation of Type A and Type B standard uncertainties [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Investigations on Measurement Uncertainty and Stability of Pressure Dial Gauges and Transducers

Yadav¹,

Gupta²,

Bandyopadhyay³

2010

Measurement Science Review

View full text Add to dashboard Cite

Several commercial instruments are available for pressure measurements. As per ISO stipulations, whenever such instruments are used for precise and accurate pressure measurements, it is obligatory on the part of measurement authority to indicate the quality of results. Stability of the pressure measuring instruments over the years is one of the important parameters in defining the quality of results quantitatively. Also, it helps the users to decide the optimum calibration interval of the particular instrument. In the present investigation, we have studied a number of analogue / digital pressure transducers / transmitters / calibrators and pressure dial gauges. The present paper describes the results of the studies carried out on several pressure dial gauges and transducers in the pressure range up to 500 MPa, calibrated several times over the years, as examples. A new approach is proposed for the establishment of measurement uncertainty for such instruments by characterizing the data obtained during calibration over the years using curve fitting.

show abstract

Comparison of an ultrasonic interferometer manometer and a static expansion system using a capacitance diaphragm gauge

Cited by 8 publications

References 10 publications

On the gas dependence of thermal transpiration and a critical appraisal of correction methods for capacitive diaphragm gauges

On the gas dependence of thermal transpiration and a critical appraisal of correction methods for capacitive diaphragm gauges

Static expansion primary vacuum standard — Part 2: Characterization of two spinning rotor gauges

Investigations on Measurement Uncertainty and Stability of Pressure Dial Gauges and Transducers

Contact Info

Product

Resources

About