Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

A gas pressure scale based on primary standard piston gauges

Published

Author(s)

Douglas A. Olson, Robert G. Driver, Walter J. Bowers Jr.

Abstract

The National Institute of Standards and Technology has redefined its gas pressure scale, up to 17 MPa, based on two primary standard piston gauges. The primary standard piston gauges are 35.8 mm in diameter and operate from 20 kPa to 1 MPa. Ten secondary standard piston gauges, two each of five series of the Ruska 2465 type, with successively smaller diameters form the scale extending up to 17 MPa. Six of the piston gauges were directly compared to the primary standards to determine their effective area and expanded (k=2) uncertainty. Two piston gauges operating to 7 MPa were compared to the 1.4 MPa gauges, and two piston gauges operating to 17 MPa were compared to the 7 MPa gauges. Distortion in the 7 MPa piston gauges was determined by comparing those gauges to a DH Instruments PG7601 type piston gauge, whose distortion was calculated using elasticity theory. The relative standard uncertainties achieved by the primary standards range from 3.0×10-6 to 3.2×10-6. The relative standard uncertainty of the secondary standards is as low as 4.2×10-6 at 300 kPa. The effective areas and uncertainties were validated by comparison to standards of other National Metrology Institutes. Results show agreement in all cases to better than the expanded (k=2) uncertainty of the difference between NIST and the other NMIs, and in most cases to better than the standard (k=1) uncertainty of the difference.
Citation
Journal of Research (NIST JRES) -
Volume
115
Issue
November-December 2010

Keywords

gas pressure scale, key comparison, piston gauge, pressure, primary pressure standard, uncertainty
Created December 6, 2010, Updated November 14, 2018