Westgas Interstate, Inc.

First Revised Volume No. 1

Effective Date: 09/01/1993, Docket: RS92- 89-002, Status: Effective

Original Sheet No. 41 Original Sheet No. 41 : Effective

GENERAL TERMS AND CONDITIONS

5. MEASUREMENT

5.1 UNIT OF MEASUREMENT AND METERING BASE. The

volumetric measurement base shall be one cubic foot of

gas at a pressure base of 14.73 pounds per square inch

absolute, at a temperature base of 60 degrees

Fahrenheit, without adjustment for water vapor.

5.2 ATMOSPHERIC PRESSURE. For the purpose of

measurement, calculation and meter calibration, the

average absolute atmospheric (barometric) pressure

shall be based on the actual altitude at each point of

measurement irrespective of variations in natural

atmospheric pressure from time to time. When

electronic computer measurement is used, the gas

pressure will be measured directly, using a pressure

measuring device for continuous input to the electronic

computer.

5.3 TEMPERATURE. The temperature of the gas shall be

determined at the points of measurement by means of a

properly installed recording thermometer or continuous

electronic transducer input to a computer of standard

manufacture selected by Transporter installed in

accordance with the recommendations contained in

ANSI/API 2530 (Orifice Metering of Natural Gas). The

The arithmetic average of temperatures for each day

shall be used in computing temperatures of the gas

during such day for conventional chart measurement.

When electronic computer measurement is used, average

daily temperature will be computed as a running average

of data determined by computer scan.

5.4 DETERMINATION OF GROSS HEATING VALUE AND SPECIFIC

GRAVITY. If Transporter has installed electronic

computer measurement equipment and field

chromatographs, the determination of gross heating

value and specific gravity shall be made from the

composition by calculation using physical gas constants

for gas compounds as outlined in GPA Standard 2145

(Table of Physical Constants of Paraffin Hydrocarbons

and Other Components of Natural Gas) with any

subsequent amendments or revisions which Transporter

may adopt. If Transporter installs conventional chart

measurement, the arithmetic average of the hourly

heating value and specific gravity recorded during