Characterization of a pneumatic differential pressure transfer standard

Abstract

The paper describes a novel method for the characterization of a pneumatic differential transfer standard in the differential pressure range 0 Pa to 3.5 MPa up to a high line gas pressure of 7.0 MPa. In view of the advances in the field of automated data acquisition systems an effort has been made to incorporate such a system in the conventional pressure measurement, which uses relatively high accuracy piston gauges and the user-friendly digital transducer. The transfer standard used in the present work is a silicon strain gauge transducer, model PMP 4115, made by Druck, with an output voltage range of 0 V to 5 V with a readout unit/power supply DPI 282. The transducer was characterized against the secondary standard, which is a twin pressure balance, Model 5502, made by Desgranges et Huot, France, designated as NPL-8. The characterization was done through an automated data acquisition system using a model 9118HR A/D interface card made by Adlink, as well as the readout unit DPI 282. The uncertainty estimations showed up considerable differences between the two modes of data acquisition. The observed results were further used to generate a regression equation for the estimation of differential pressure at any given line pressure.