Results on the effective area of the FPG-type digital piston manometer of MIKES

摘要

The Centre for Metrology and Accreditation (MIKES) has been using a new type of a digital piston manometer (force-balanced piston gauge (FPG)) since 2001. The instrument was developed by DH Instruments Inc., USA. Determination of the effective area was an essential part in validating the FPG in MIKES. One of the big advantages of the FPG is the fact that a conventional pressure balance can be used to determine the effective area. However, the measurement is not straightforward due to the lubrication gas flow in the FPG. The effective area of the MIKES FPG has now been determined several times in the gauge mode by MIKES, once by NMi-VSL, The Netherlands, once by SP, Sweden, and twice by the manufacturer. Measurements in absolute mode have been made using the mercury column manometer of the Physikalisch-Technische Bundesanstalt, Germany. The measurement methods and the results are described in the paper. The results of measurements in MIKES from 2001 to 2004 illustrate the long-term stability and reproducibility of the instrument.