Performance aspects of gas-operated pressure balances as pressure standards

Abstract

In this paper, the aspects of gas-operated pressure balances that affect their performance are discussed. These aspects include both the features that make gas-operated pressure balances suitable for use as pressure standards and the factors that must be managed to achieve good performance. As key features, gas-operated pressure balances are pressure generators, have excellent relative short-term stability (∼5 × 10−9) and long-term stability (∼1 × 10−6), and can be used as primary standards. Factors to manage include harmonic oscillation of the piston in the cylinder, pressure balance temperature and operating height, and geometric imperfections. Three applications are used to illustrate the performance aspects of gas-operated pressure balances: a primary standard, a standard for differential pressure from <1 Pa to >1000 Pa and a standard for absolute pressure from <10 Pa to 10 kPa.