TransColorado Gas Transmission Company

Original Volume No. 1

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Effective Date: 12/05/1996, Docket: CP90-1777-009, Status: Effective

Original Sheet No. 60 Original Sheet No. 60 : Superseded





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.


10.3 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 TransColorado

installed in accordance with the recommendations contained in

ANSI/API 2530 (Orifice Metering of Natural Gas), as amended from

time to time. 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.


10.4 Determination of Gross Heating Value and Specific Gravity. Since

TransColorado 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 that

TransColorado may adopt.


Should TransColorado elect to install conventional chart

measurement, the arithmetic average of the hourly heating value

and specific gravity recorded during periods of flow each day by a

recording calorimeter and gravitometer or recording chromatograph,

if installed, shall be considered as the gross heating value and

specific gravity of the gas delivered during each day.


If a continuous gas sampling device is used, determinations shall

be made not less than once every month. Such determinations shall

be considered as the gross heating value and specific gravity of

all gas delivered during the applicable sampling period. Gross

heating values and specific gravities determined from spot samples

will be used