Flow meters are devices used to measure the volume or mass of a gas or liquid.  They are also referred to as flow gauge, flow indicators, liquid meters, and flow rate sensors.   Depending on the particular industry, they all measure flow.

What are the various types of flow meters?

1. Positive Displacement ( or Volumetric flow meter or PD flow meter)
Positive displacement flow meters are unique as they are the only meter to directly measure the actual volume.  All other types infer the flow rate by making some other type of measurement and equating it to the flow rate.
2.  Mass
The output signal is related to the mass passing through the meter.  Thermal and Coriolis flow meters fall into this category.
3.  Velocity
The output signal is related to the velocity passing through the meter.
                1. Electromagnetic
                2. Ultrasonic
                3. Turbine, Propeller, and Paddle Wheel
                4. Vortex Shedding
                5. Target
                6. Variable Area and Rotameter
                7. Orifice Plate, Open channel, Flow Nozzle, Laminar, Venturi, and Pitot Tube

Best Practices to Follow
Some of the best practices to follow for flow meter calibration that ensure you meet quality standards:

Show Traceability

  • The calibration of a flow meter is conducted by comparing its readings against a standard, under controlled test conditions.
  • For successful flow meter calibration, the measurements from the standard device used for comparison must be traceable to national/international industry standard

  • Accuracy - Uncertainty
    • To correctly assess accuracy, the test device and standard should measure the same quantity of liquid or gas, under the same conditions.
    • Uncertainty values must be determined and recorded, since the do affect accuracy.
    • Every step in the traceability chain will lower the uncertainty.
  • Understand Fluid Properties
    • Other than quantity, the properties of the fluid or gas being measured also have to be taken into account.
    • These cause it to interact with the flow meter and changes in this interaction can affect the measurements given by the device.
  • Installation Condition
    • Other factors that could affect a flowmeter’s readings include:
      • Vibrations
      • Electronic interference
      • Flow disturbances
    • The installation of the standard device used for reference should also be as similar to the test devices installation conditions as possible.
  • Lab Accreditation
    • Accreditation by a calibration laboratory or service provider establishes that traceability standards have been met and uncertainty recorded and proper procedures have been used during a flow meter calibration.
    • This gives clients the confidence that stated expectations have been achieved.

If you use a flow meter in your business, our expert technicians here at Scientific Instrument Center can help you calibrate your flow meter.  
Contact us or give us a call 614-771-4700 to set up a schedule for regular calibration services.  Our qualified professionals will check your equipment to make sure it is functioning properly before your next regulatory inspection.