What are the calibration or verification methods of electromagnetic flowmeter

　　Electromagnetic flowmeter calibration is sometimes also called calibration or verification. In fact, calibration includes two aspects: 1. Transfer the value to the instrument to determine the position of the flow scale mark (or determine the signal output by the flow scale); 2. Adjust the output of the water flow meter to compare with the standard value (reference value) to determine the accuracy of the water flow meter and determine its error value.

　　There are two methods for flow calibration of water flowmeter (also called electromagnetic flowmeter) - direct measurement method and indirect measurement method. Direct measurement method is also called real flow calibration method, which is to measure the flow of the actual fluid through the instrument to be calibrated by other standard devices (standard flowmeter or flow standard measuring instrument), and compare it with the flow value of the instrument to be calibrated. Some people call this method wet calibration. The flow value obtained by real flow calibration method is both reliable and accurate, and is currently adopted by many flow meters (such as electromagnetic flowmeter, vortex flowmeter, steam flowmeter), and is used as a method to establish standard flow.

　　Before leaving the factory, water flow meters (also called electromagnetic flow meters) are calibrated in real flow on flow calibration standard devices (sometimes referred to as flow standard devices or flow calibration devices). Users should also perform real flow calibration on flow calibration standard devices for instruments that have been regularly calibrated and repaired. Flow calibration standard devices are established in accordance with relevant standards and verification regulations, and are certified by specialized agencies authorized by the state. They are devices that can transfer flow values ​​and are calibration equipment that provides flow values. Their values ​​can be traced back to national metrological reference quantities for mass, time and temperature.