Calibration methods for negative gauge pressure down to  −100 kPa

Abstract

The measurement of negative gauge pressure is a field of increasing importance in science and industry. One of the main aims of the EMPIR Joint Research Project 14IND 06 pres2vac is to develop guidelines for it. We present a comparison of three different methods for measuring negative gauge pressure: (i) using two absolute pressure measuring instruments, (ii) generating a negative gauge pressure in the bell jar of the pressure balance, and (iii) using a 'hanging piston' pressure balance. The advantages and drawbacks are discussed and some preliminary results presented.

Recent research results on piston gauges

“…From the ratio of capacitances measured by a capacitor filled with a gas at pressures p and 0, C(p) and C(0), the relative dielectric constant of gas () can be determined by (3). Herewith, the gas molar density () and p can be calculated using equations ( 4) and (5).…”

“…With new commercially available force-compensated piston gauges [3], [4], it became possible to measure absolute and gauge pressures down to 1 Pa, which raised the question about traceability of these novel piston gauges at low pressures. Industrial needs for accurate negative and low positive gauge pressure measurement required suitable reference standards and calibration methods, which could be established using piston gauges [5].…”

Analytical solutions of some model cases of piston-cylinder assemblies

“…The most important standard of the CMI for medium pressures in gas medium is a set of pressure balances, PG7601, manufactured by Fluke-DHI. They cover gauge and absolute pressures in the range from cca 10 kPa to 10 MPa, but with some modifications the instrument can also be used for negative gauge pressures [19,20]. This standard successfully participated in several comparisons registered within the key comparison data base, see [21][22][23][24][25][26].…”