Comparisons to establish a force-balanced piston gauge and a spinning rotor gauge as the new measurement standards of MIKES

Abstract

Centre for Metrology and Accreditation (MIKES) has worked towards expanding its calibration capabilities in the absolute pressure range downwards from 0.2 Pa and lowering measurement uncertainties in the range <10 kPa using a force-balanced piston gauge (FPG) and a spinning rotor gauge (SRG). MIKES was the first national pressure laboratory to purchase a novel type of piston manometer, FPG, developed by DH Instruments Inc., USA. The effective area of the FPG was at first determined at MIKES by a comparison with a conventional pressure balance. The result was confirmed in comparisons in the same pressure range with two other laboratories, Swedish National Testing and Research Institute (SP), Sweden and Institute for Metrology and Technology—Van Swinden Laboratorium (NMi-VSL), Netherlands. Next a direct comparison with the mercury column manometer of Physikalisch-Technische Bundesanstalt (PTB), Germany in the absolute pressure range from 1 to 15 kPa was carried out. Use of the FPG for calibration of capacitance diaphragm gauges (CDGs) is also presented. MIKES now uses two SRGs as reference standards, manufactured by MKS Instruments, Inc., USA. A comparison of SRGs in the range from 0.1 to 5 Pa between MIKES, SP and Vaisala Oyj accredited laboratory was performed in 2001–2002.