Development and characterisation of a low pressure transfer standard in the range 1 Pa to 10 kPa

Abstract

We describe a transfer standard for low absolute and gauge pressure in the range 1 Pa to 10 kPa. This transfer standard is composed of three differential capacitance diaphragm gauges (CDGs) of full-scale 130 Pa, 1.3 kPa and 13 kPa respectively and one absolute 130 kPa resonant silicon gauge (RSG). The objective for the relative uncertainty contribution (<em>k</em>=1) of this standard during a comparison is a few tens of ppm at 10 kPa to a few hundred ppm at 1 Pa. It relies on a good long-term stability of the calibration slope of the RSG used, between 5 kPa and 10 kPa, disseminated to CDGs in absolute mode and subsequently in gauge mode. The methods to assess such uncertainty and the preliminary characterisation of the transfer standard are presented.