Development of a new high-stability transfer standard based on resonant silicon gauges for the range 100 Pa to 130 kPa

Abstract

The National Institute of Standards and Technology (NIST) has developed a new transfer standard capable of absolute-mode and differential-mode operation in the range 100 Pa to 130 kPa. This newly built transfer standard relies on resonant silicon gauges (RSGs) of the same type used to provide superior long-term calibration stability in NIST piloted international key comparisons CCM.P-K4 and CCM.P-K5, which covered absolute and differential pressure standards pressures up to 1 kPa (Miiller et al 2002 Metrologia 39 Tech. Suppl. 07001 and 07002). The new transfer standard package differs from the previous packages in that it fully covers the atmospheric pressure range (100 Pa to 130 kPa). This was made possible by the addition of a pair of 130 kPa RSGs to complement a pair of 10 kPa RSGs. The RSG transfer standard package has demonstrated good short-term zero stability and pressure resolution, and has demonstrated long-term instability of only a few ppm at 130 kPa, increasing to 0.01% at 100 Pa. The long-term instability is nominally commensurate with that associated with piston gauge standards, which are limited to pressures of nominally 10 kPa and higher. The main advantage of the new package is that it operates easily at lower pressures than piston gauges while still covering the atmospheric pressure range 100 Pa to 130 kPa.

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

“…On the basis of earlier comprehensive reviews of pressure transducer performance [3,19], two types of gauges were selected as the transfer standards, namely, resonant silicon gauges (RSGs) for their good long-term stability and capacitance diaphragm gauges (CDGs) for their high-precision. The RSGs are a type of MEMS (micro-electromechanical systems) sensor that have excellent calibration stability, are resistant to mechanical shock, and are only moderately susceptible to overpressure although they are rather sensitive to tilt (≈ 0.4 Pa/mrad).…”

“…This is due to the limited number of repeat calibrations against the same standard and the unknown effect of transportation between laboratories (rough handling, large temperature changes, etc.). Earlier studies at the pilot laboratory [3,19] have shown that changes in response functions of CDGs and RSGs between calibrations generally do not occur as a monotonic drift with time (over intervals of months to years) but rather as shifts that are essentially random in both sign and magnitude. Furthermore, the earlier studies showed that, at least for low range CDGs, the magnitude of the shifts was on average about a factor of two larger for gauges transported between laboratories than for gauges maintained at the pilot laboratory.…”

“…These standards include manometers and non-rotating force-balanced piston gauges (FPG) that operate in the range of this comparison (1 Pa to 10 000 Pa absolute) [2]. It was decided that NIST’s experience in the previous low pressure comparison and detailed knowledge in the design and construction of high-stability resonance silicon gauge transfer standard packages [3,4] made it well suited to be the pilot. NIST completed construction and testing of two new high stability transfer standard packages capable of absolute pressure measurements spanning the extended range of 1 Pa to 10 000 Pa.…”

Long-term stability and zero drift of digital barometric pressure gauges

“…To optimize the performance of these pressure gauges in high-accuracy measurements, it is necessary to know their characteristics and correct the indication properly [1]. For example, some studies have been performed to determine the long-term behavior of pressure gauges for high-accuracy metrology and inter-laboratory comparisons of pressure standards [2][3][4]. The characterization work in this paper also helps those activities.…”

Calibration of Capacitance Diaphragm Gauges with 1333 Pa full scale by Direct Comparison to Resonant Silicon Gauge and Static Expansion System

“…One is a direct comparison to the resonant silicon gauge (RSG), which is calibrated by the pressure balance. The RSG is used as a reliable transfer gauge in the field of pressure and vacuum standards [10,11]. The other is the static expansion system [4].…”