Reference Values of the Dielectric Constant of Natural Gas Components Determined with a Cross Capacitor

Published

May 1, 2001

Author(s)

Michael R. Moldover, T J. Buckley

Abstract

We used a novel toroidal cross capacitor to measure accurately the dielectric polarizability e(p) (i.e., the dielectric constant) of helium, argon, nitrogen, methane, and carbon dioxide at T = 50 degrees C. The data extend up to 7 MPa (5 MPa for CO₂) and may be useful for calibrating on-line, capacitance-based systems that are designed to measure the heating value of natural gas. The uncertainties of e, and p are 6 and (3.0 10^-5 p + 84 Pa), respectively. We used the properties of helium calculated ab initio from quantum mechanics to verify that the cross capacitor deformed in a predictable manner under hydrostatic (gas) pressure. Thus, we avoided a common cause of systematic errors in measuring the dielectric constant of gases.

Citation

International Journal of Thermophysics

Volume

22

Issue

No. 3

Pub Type

Journals

Keywords

argon, carbon dioxide, cross capacitor, dielectric constant, dielectric polarizability, helium, methane, molar polarizability, natural gas

Citation

Moldover, M. and Buckley, T. (2001), Reference Values of the Dielectric Constant of Natural Gas Components Determined with a Cross Capacitor, International Journal of Thermophysics (Accessed October 10, 2025)