Reduction of the uncertainty of the PTB vacuum pressure scale by a new large area non-rotating piston gauge

Abstract

This paper describes the metrological characterization of a new large area piston gauge (FRS5, Furness Rosenberg Standard) installed at the vacuum metrology laboratory of the Physikalisch-Technische Bundesanstalt (PTB). The operational procedure and the uncertainty budget for pressures between 30 Pa and 11 kPa are given. Comparisons between the FRS5 and a mercury manometer, a rotary piston gauge and a force-balanced piston gauge are described. We show that the reproducibility of the calibration values of capacitance diaphragm gauges is enhanced by a factor of 6 compared with a static expansion primary standard (SE2). Improvements of the SE2 performance by reducing the number of expansions and smaller uncertainties of expansion ratios are discussed.

Final report on the key comparison CCM.P-K4.2012 in absolute pressure from 1 Pa to 10 kPa

“…The evaluation of the FRS5 was described in publication [12]. The uncertainties can be approximated by the formula: $$(k=1)u=\sqrt{4.62\times {10}^{-4}{\text{Pa}}^2+p\times 1.08\times {10}^{-8}\text{Pa}+p^2\times 5.54\times {10}^{-10}}(\ge 30\text{Pa}\text{to}10\text{kPa}),$$ where p is the pressure in Pa.…”

Realization of ppm level pressure stability for primary thermometry using a primary piston gauge

“…Bock et al at PTB [25] discovered that by using a large area non-rotating piston gauge, they were able to reduce the uncertainty of their vacuum pressure scale. This approach was followed in the present work.…”

“…To prevent this from being a problem, therefore, we should not only isolate the pressure oscillation from the surroundings (external pressure-noise), but more importantly isolate the pressure change due to the piston gauge (internal pressure-noise). [25] discovered that by using a large area non-rotating piston gauge, they were able to reduce the uncertainty of their vacuum pressure scale. This approach was followed in the present work.…”

Novel method for the realization of small differential pressures between 1 Pa and 1 kPa

“…New force-balanced piston gauges (FPGs) allow an accurate measurement of pressures from 15 kPa downwards to zero with an accuracy level down to 6×10 5 pe + 5 mPa [2,3], where pe determines the external pressure. FPGs have been used so far as secondary standards only.…”