Thread Content
Most verification tests for electromagnetic flowmeters are conducted with liquid flowing through the flowmeter and a calibration standard device or reference flowmeter. Care should be taken to ensure uniform and stable flow of the liquid in the experimental pipeline, free from sudden fluctuations in local velocity caused by disturbances. Such disturbances frequently occur within the Reynolds number range specific to industrial process conditions. There are several methods for evaluating the performance of electromagnetic flowmeters: 1. It is necessary to maintain close communication between the evaluation team and the manufacturer. When designing the experimental procedure, attention should be paid to the manufacturer’s technical specifications regarding the appearance, and the manufacturer should be consulted for feedback on the experimental procedure and results. 2. The reference flow meter or calibration standard device should be of an appropriate scale that can encompass the flow range of the flow meter under test. If flow meters are required to be installed in testing equipment, then such testing equipment must meet certain specifications: the accuracy class of the reference standard system should be at least twice as good as that of the equipment being tested. 3. During the experimental period, any adjustments made to the electromagnetic flowmeter must be recorded, and the effect of these adjustments on performance under reference conditions must be determined and expressed as a percentage of the output range. 4. At the inlet of the upstream straight pipe, the flow should be axially symmetric, with no significant pulsations or vortices.