Page 12 - Pressure Calibration Brochure

Gas custody transfer low

computer calibration

Gas custody transfer low computers that calculate
low in pipelines by measuring the differential

pressure across a low restriction, such as an
oriice plate or other differential pressure low

device, require special calibration to perform at

optimum accuracy. Gas low computers make
three primary measurements to calculate low:

volumetric low (difference in pressure across the
oriice plate), static pressure in a pipeline and gas

temperature. A calculation is performed using this
data to determine the actual mass and volume of

the gas lowing through the pipeline.
These calibrations can be made with three

separate calibrators, a low pressure, high pressure
and a temperature calibrator or use a multifunction

calibration tool designed for this speciic task.
An example of a calibrator purposed for this

task is the Fluke 721 or 721Ex. It has two built-
in pressure ranges and the ability to measure

temperature. The most popular coniguration is
16 psi/1 bar on the low pressure (P1) sensor side

and 1500/100 bar or 3000 psi/200 bar on the high
pressure (P2) sensor side. It measures temperature

using a precision RTD accessory and can display all
three measurements at once if desired.

Suggested test tools

Fluke 721 Fluke 700G Fluke 754 Fluke 750P Series
Precision Dual Precision Pressure Documenting Pressure Modules

Range Pressure Gauge Calibrator
Process See pg 23
Calibrator
Calibrator-HART
See pg 26
See pg 25
See pg 23

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