How to Calibrate a Flow Meter

A flow meter is a test device used to measure the flow of process fluids and gases in industrial plants and facilities. Common flowmeters include electromagnetic flowmeters, mass flowmeters, turbine flowmeters, vortex flowmeters, orifice plate flowmeters, and ultrasonic flowmeters. Flow rate is the rate at which a process fluid passes through a pipe, orifice plate, or vessel in a given amount of time. Control and instrumentation engineers measure this value to monitor and adjust the speed and efficiency of industrial processes and equipment.

Ideally, test equipment must be “reset” from time to time to prevent inaccurate readings. However, due to aging electronics, coefficient deviations, etc., in industrial environments flowmeters are calibrated periodically to ensure accurate measurements for safe and timely operation.

What is Flow Meter Calibration?

Flowmeters are tested and calibrated in accordance with the calibration protocols issued by the National Bureau of Weights and Measures (NBWM) for various types of flowmeters. The applied flowmeters, with the exception of standard throttling devices, which do not have to be experimentally calibrated, are usually calibrated in-house by the flowmeter flowmeter manufacturer after production or sent to an independent calibration organization for adjustment.

Flow rate is an important parameter in the automated production processes of petroleum, metallurgy, electric power, chemical industry, pharmaceuticals, food and so on. Flow measurement calibration is indispensable from process monitoring to product quality inspection. Flow measurement calibration supervision level is also directly related to the quality of production, production efficiency and energy utilization.

Calibration Process

• Flow standard device calibration method: this is the most commonly used method. The flowmeter to be calibrated is measured against a standard flowmeter, and the accuracy of the flowmeter is assessed by comparing the results of the two measurements. This method needs to ensure the accuracy of the standard flow meter itself.

• Physical calibration method: in some cases, you can use the actual fluid for calibration. This method is more practical and intuitive, but need to ensure that the characteristics of the calibration medium and the flowmeter using the same medium to ensure the accuracy of the calibration results.

• Standard equation calibration method: For some specific types of flowmeters, such as flowmeters with linear output characteristics, calibration can be carried out by establishing a standard equation. This calibration method is based on the relationship between the input and output of the flow meter.

Calibration of flow meters is very important. If a flowmeter is not calibrated correctly, it may lead to measurement errors that can affect the production process and product quality. After a period of time, a flowmeter may change its performance for a variety of reasons. Therefore, in addition to the initial calibration, periodic rechecks are required to ensure their continued accuracy and reliability.