Electromagnetic flowmeters have high stability, and the instrumentation equipment itself generally rarely fails. However, due to changes in environmental conditions or limited installation conditions, some problems or failures have also occurred, which should be resolved or avoided, mainly in the following situations: ①The installation conditions of the flowmeter are not met. The requirements for straight pipe sections are relatively high, which can be met as much as possible in the design of new water plants, but for the renovation or installation of old water plants, the above conditions have become almost harsh. This affects the measurement stability. The solution is to install a rectifier tube to improve the flow characteristics. ②The flow rate of the measured water is too low, which affects the accuracy of the measurement. Especially the flowmeter installed at the boundary of some areas, because it is at the end of the pipe network of the regional company, the pressure difference is small, which causes the flow velocity to be too low. The solution is to open the valves on both sides of the boundary as much as possible. ③ There is gas in the pipeline water, which causes large measurement fluctuations and affects stability. The solution is to try to find the source of the gas and solve it, and install an exhaust valve in the pipeline when necessary. ④The surface of the sensor electrode of the flowmeter installed in the raw water pipeline is contaminated by silt deposits, which affects the measurement. The solution is to choose a knife electrode and regularly maintain and clean it. ⑤The converter of the electromagnetic flowmeter is damaged due to lightning strikes, making it impossible to measure. The solution is to install corresponding lightning arresters on the converter signal input terminal, excitation current input terminal and working power terminal respectively. ⑥ The accumulation of foreign matter in the electromagnetic flowmeter’s population pipeline causes a sudden change in the flow characteristics of the measured water body, which affects the measurement accuracy and causes larger errors. The solution is to remove foreign objects accumulated in the pipeline in time.
Post time: 21-09-21