DETERMINATION OF THE EFFECTIVE AREA OF A GAS-PRESSURE BALANCE FOR LOW PRESSURES

Bogdan Blagojevic, Ivan Bajsic
Abstract:
This paper describes our attempts to determine the effective area of a pressure balance (Type V1600/4D, manufactured by Pressurements, Ltd.) that is used in our pressure-calibration laboratory as a standard pressure balance for gauge and differential pressure measurements. The gauge measuring range of this gasoperated balance extends from a nominal pressure of 20 Pa up to 16 kPa, and its minimum differential pressure measurement is 5 Pa. This pressure balance is a "discrete" system, and therefore it has several pistons and weights. In the measuring range from a nominal pressure of 400 Pa up to 16 kPa only two different pistons are used. From the calibration results relating to pressure and mass provided by the calibration laboratories of the NPL and Lm (Mass Laboratory of the MIRS) we derived an approximate formula for the effective area. This equation shows the nonlinearity of the pistons’ effective area. Good agreement between the indirectly measured and the approximated values of the effective area was obtained, and their deviations are more than four times smaller than the accuracy of this balance. Knowing the effective area of the piston will reduce the number of discrete calibration points that are required.
Keywords:
pressure balance, effective area, gauge and differential pressure
Download:
PWC-2003-TC16-002.pdf
DOI:
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Event details
Event name:
XVII IMEKO World Congress
Title:

Metrology in the 3rd Millennium

Place:
Dubrovnik, CROATIA
Time:
22 June 2003 - 28 June 2003