Calibration system for high gas pressure measuring devices

The National Metrology Institute of Japan, AIST has developed a high gas pressure standard and a calibration system for pressure measuring devices. The maximum pressure is currently 20 MPa and will be extended to 100 MPa. The calibration system is mainly composed of a liquid-lubricated gas pressure balance, an automatic weight handler, a gas pressure controller, and a gas booster. The effective area of the piston-cylinder assembly installed in the liquid-lubricated gas pressure balance is determined beforehand from the comparison against the hydraulic pressure standard, which is maintained by the hydraulic pressure balances. In this article, the details of the high gas pressure standard and the configuration of the calibration system developed are described. The method for calibrating a pressure measuring device using the system and its result are also presented.