In recent years, with the continuous improvement of the automation technology level of the water supply industry and the requirements of trade settlement and measurement, the application and promotion of electromagnetic flow meter have become increasingly common. Especially in the water supply industry, the electromagnetic flow meter has been widely recognized.
(1) Since the measurement results are independent of the physical parameters such as liquid pressure, temperature and conductivity, the measurement accuracy is high and the work is reliable.
(2) The electromagnetic flow meter measures the open flow in the pipe, so there is no additional pressure loss, which means there is no additional head loss for tap water measurement.
(3) Only the pipe and the electrode are in contact with the measured liquid. Therefore, as long as the electrode material is selected reasonably, the requirements of corrosion resistance and wear resistance can be achieved. It has the characteristics of long service life and low maintenance requirements.
(4) The electromagnetic flow meter can measure the flow of positive and negative fluid.
(5) The output signal mode of the electromagnetic flow meter is flexible, and there are pulse, current, frequency and other methods.
(1) The upstream pipe of the electromagnetic flow meter has a straight pipe section of at least 5 times the length of the pipe diameter, and the downstream has a straight pipe section of at least 3 times the length of the pipe diameter. If permitted, the length of the front straight pipe of the electromagnetic flow meter can be extended to more than 10 times the pipe diameter.
(2) In the installation of the electromagnetic flow meter, the sensor grounding ring should be reliable.
(3) It is necessary to pay attention to avoid external electromagnetic interference in the selection of the use environment, especially to avoid the interference of power frequency electromagnetic field.
(4) A valve should be installed outside the leading distance in the upstream pipe of the electromagnetic flow meter. In the case of butterfly valves or right-angle bend pipe which seriously affects the flow characteristics, it is best to install a rectifier in a straight pipe with a diameter of 5-10 times the diameter of the upstream of the electromagnetic flow meter. The aim is to stabilize the flow pattern and improve the measurement accuracy.