Calibrating flow meters: how, when and why


Erik Smits, Manager Liquid Flow Metrology at VSL discusses the factors to consider when calibrating flow meters in pipelines systems, in the September 2021 issue of World Pipelines, the leading international magazine for the industry that transports gasses and liquids through pipeline systems. 


In different industries, flow in pipelines needs to be measured with different accuracies. Accuracy is defined according to the importance of the quantity of liquid, gas or a combination of these, measured in processes aimed at safety, quality control or billing. 


Flow meters are initially calibrated to demonstrate accuracy, but flow meters are also calibrated when standards, legislation, contracts or other written documents prescribe mandatory calibrations to demonstrate changes in the flow meter's measured value(s). The interval between calibrations is determined by the need to ensure that flow meters continue still perform within the accuracies and/or tolerances established in the procedures of the companies using them.  


For on-site calibrations of an installed flow meter, special connections must be available to connect the mobile equipment to the process. When on-site calibration is not possible, the flow meter can be sent to a calibration facility, laboratory or even back to the manufacturer. In some cases, flow meters cannot be calibrated in the application or cannot be taken out due to the operation. In this case you can only calibrate on-site and when the application is not in use during for example maintenance. However, delays of a calibration can affect safety, health or the financial results of a company. 


Read the World Pipelines article here to learn more about the need for flowmeter calibration or contact VSL for more information.