Comparison in gas media (absolute and gauge mode)in the range from 25 kPa TO 200 kPa (EURAMET.M.P-K8)

Abstract

It was decided at the EURAMET TC-M meeting in Torino in 2006 to realize a comparison in gauge and absolute pressure up to 200 kPa as it would allow establishing a link to the CCM.P-K6 and CCM.P-K2 comparisons. This project from the beginning interested a lot of laboratories with participants, 22 of which have submitted results. The circulation of the transfer standard began on July 2009 and lasted until January 2012. No major problem occurred during the transport.The mesurand of the comparison is the effective area of a piston-cylinder determined in gauge and absolute pressure from 25 kPa to 200 kPa with pressure steps of 25 kPa. The transfer standard is a gas lubricated tungsten carbide piston-cylinder with an effective area of ~9.8 cm 2 , fabricated by DH Instruments and compatible with a PG-7601 pressure balance. Some participants used their own pressure balance while a pressure balance with a reference vacuum sensor has been circulated for the participants not equipped with this system.One participant (SMU, Slovakia) has never provided the measurement results and another participant (FORCE Technology, Denmark) submitted a revised set of measurement results after the pilot laboratory mentioned that the equivalence was not met.After the determination of the reference value, all the 22 participants who delivered the results in gauge pressure demonstrated equivalence respective to the reference value on most of the range. In absolute pressure the equivalence is demonstrated, for all nominal pressures, by all 17 participants who submitted results.

Analytical solutions of some model cases of piston-cylinder assemblies

“…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]. Its most important part consists of three nominally 10 cm 2 PCAs made of tungstencarbide or hard ceramics.…”