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Suggested test tools
Gas custody transfer flow
computer calibration
Gas custody transfer flow computers that calculate
flow in pipelines by measuring the differential
pressure across a flow restriction, such as an
orifice plate or other differential pressure flow
device, require special calibration to perform at
optimum accuracy. Gas flow computers make
three primary measurements to calculate flow:
volumetric flow (difference in pressure across the
orifice 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 flowing 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 specific 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 configuration 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.
Fluke 754
Documenting
Process
Calibrator-HART
See pg 5
Fluke 700G
Precision Pressure
Gauge Calibrator
See pg 13
Fluke 721
Precision Dual
Range Pressure
Calibrator
See pg 12
Fluke 750P Series
Pressure Modules
See pg 12
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Pressure Applications