Metering Research Facility


Flow Meter Calibration and Testing Services


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  Image: Electronic flow measurement (EFM) at MRF

Electronic flow measurement (EFM) at MRF

Calibrations in the Metering Research Facility (MRF) typically consist of multiple flow rates (6 to 10) at a single pressure and temperature. At each flow rate, six consecutive 90-second runs are performed to verify meter repeatability. Because critical flow nozzles are used for flow control and measurement, there are discrete flow rates available in either loop based on the nozzle combination.


Flow points specific to your test conditions can be estimated by using the online flow calculator. A standard calibration generally takes two days—the first day for installing the meter, related piping, and secondary instrumentation (pressure and temperature transmitters supplied by the MRF) and the second day for the flow test.


If you have specific testing/calibration needs, please contact the MRF or fill out the online test request form.


Standard flow meter calibrations are typically performed in one of the two legs of the HPL test section or in one of the parallel branches of the LPL. Special piping arrangements to replicate field installations can also be accommodated in the facilities. The test ranges available are shown in the following table.


MRF Performance Specifications




Maximum Flow Rate, MSCFH



Maximum Flow Rate, ACFH



Pressure, psig

150 to 1,100

50 to 200

Temperature, Gas F

40 to 150

40 to 150

Pipe Size, inch

2 to 20

1 to 8

Specific Gravity**

0.55 to 0.97

0.55 to 0.97

Test Fluid

Natural Gas/N2


Primary Flow Standard

Weigh Tank

Weigh Tank


  *Maximum flow rate with sonic nozzle flow control. Higher flow rates are available, but without sonic
 nozzle flow control.

**The typical specific gravity of natural gas at the MRF is approximately 0.57


Measurement Accuracy


Measurement Accuracy*

Flow Rate

0.1 to 0.25% (R)


0.015% (F) of value


0.05 °F (F)

Specific Gravity

0.05 (R)

Reynolds No.

1.0% (R)


                           *R = Reading

                            F = Full Scale

Flow Calculator


To find out how the Metering Research Facility can assist you with flow measurement, meter development, calibration, testing, and training, or for information about how you can contract with Southwest Research Institute (SwRI), please contact Terry Grimley at tgrimley@swri.org or (210) 522-2353.




Contact Information

Terry Grimley

Metering Research Facility

(210) 522-2353


Michael Robertson

(210) 522-5922



Related Terminology

flow meter calibrations

gas meter

gas sampling

orifice meter

ultrasonic meter

natural gas

flow conditioner

turbine meter

flow meter

Related Information

Flow Calibration Laboratory Performance: What Should Your Expectations Be?

Fluids and Machinery Engineering Dept

| Fluids and Machinery Engineering Department | Mechanical Engineering Division | SwRI Home |


Southwest Research Institute® (SwRI®), headquartered in San Antonio, Texas, is a multidisciplinary, independent, nonprofit, applied engineering and physical sciences research and development organization with 10 technical divisions.

August 06, 2014