Best Practices for Calibrating Your Flow Meter

A flow meter is a special device that measures the amount of gas or quantity of liquid or its flow rate moving through the pipe. Too little or too much gas or liquid flowing through the pipe may result in the malfunctioning of the machine. A proper reading is imperative at all times. Flow meters are used by measurement and test professionals in applications that depend on accurate flow measurements such as in utilities, energy, aerospace, water management, HVAC, pharmaceuticals, and agriculture industries.

There are specific best practices that need to be implemented to receive the most accurate results from your flow meter. These five best practices for calibrating flow meter are:

1: Calibration Standard

Proper calibration depends on a standard that is accurate. Thus, the calibration has to be even more precise than the flow meter it will measure. According to industry standards, the rule of thumb regarding calibration standard is, that it has to be four times more correct than the flowmeter that is tested. However, this rule of thumb may adapt depending upon specific requirements of the test.

A cost is also associated with seeking the most accurate calibration standard. The cost is proportionate to the breadth and quantity of test points recorded. Differential-producing meters are used to acquire these data points. Some of these meters may include several sets of piezometers, which will increase the cost. Thus, base price is determined first which includes a pre-decided number of data points and taps.

2: Traceability

This best practice is an important and necessary form of documentation. It measures the standard as per which the flowmeter is calibrated. The standard used to calibrate your flow meter should be traceable to one that is recognized within the industry. Doing so helps to authenticate that the calibration system is capable of accurately calibrating the flow meter.

3: Rate of Flow

As a rule, the flow rate between the flow meter and the calibrator has to be consistent. Since calibration readings are actuated in real time based on the flow received from the flow meter, the flow must be constant to obtain a sound reading. It requires a thorough understanding of the properties of gas and fluids that are measured. Their properties have an effect on the flow meter and variations in these interaction affect measurements provided by your device.

4: Consistent Measuring

Apart from evaluating calibration methods, the flow meter needs to be examined to ensure the absence of significant issues that may alter the accuracy of measurement. A certified service provider or calibration laboratory can ensure that proper measurement procedures are followed, uncertainty is recorded, and the traceability standards are met.

5: Simulation

When the calibration test is being performed, efforts should be taken to ensure that the same conditions should be maintained as when the flow meter operates. There are specific factors, which can influence how a flow meter will operate. These are:

  • Vibrations
  • Flow disturbances at the site
  • Electronic interference
  • Heat content of the gas or liquid measured
  • Viscosity
  • Density

By adhering to the five best practices mentioned above: maintaining calibration standards, traceability, simulation, consistent measuring by an accredited professional and rate of flow, you will ensure that your flow meter is giving out accurate measurements.


Proteus Industries develops, manufactures and markets a full line of instruments and controls for fab and semiconductor equipment industry. Proteus products are used in virtually every semiconductor fab around the world.