Electromagnetic FlowmeterWidely used in industries such as petroleum, chemical, metallurgical, textile, food, pharmaceutical, papermaking, as well as environmental protection, municipal management, water conservancy construction, etc. The measurement principle is Faraday's law of electromagnetic induction, which is an instrument that measures the flow rate of a conductive fluid based on the induced electromotive force when the fluid passes through an external magnetic field. The main components of the sensor are the measuring tube, electrode, excitation coil, iron core, and magnetic yoke housing. Description of Electromagnetic Flow Meter Equipment ① The transmitter should be installed indoors in a monotonically ventilated area. Avoid placing the equipment in areas with high ambient temperatures, avoid severe vibrations, and try to avoid equipment with strong magnetic fields, such as large motors, transformers, etc. Avoid placing the equipment in environments with corrosive gases. The equipment address should be easy to repair. This is the environmental condition that ensures the normal operation of the transmitter② Valves and bypasses should be installed at both ends of the transmitter③ In order to ensure that the measuring tube of the transmitter is filled with the measured medium, the inverter is installed vertically with a flow direction from bottom to top. Especially for liquid-solid two-phase flow, it is necessary to install vertical equipment. If only horizontal equipment is allowed on site, it is necessary to ensure that the two electrodes are in the same horizontal plane④ To avoid disturbing the signal, it is necessary to transmit the signal between the transmitter and the converter using shielded wires. It is not allowed to parallel the signal cable and power cord in the same cable steel pipe. The length of the signal cable should generally not exceed 30m⑤ The millivolt communication potential measured by the electrodes of an electromagnetic flow transmitter is based on the liquid potential inside the transmitter. In order to stabilize the liquid potential and maintain equal potential between the transmitter and the fluid to ensure stable measurement, the transmitter housing and metal tube should have a prominent grounding at both ends, and the converter housing should also be grounded. The grounding resistance should not exceed 10 and should not be shared with the grounding wire of other electrical equipment. Assuming that outstanding contact between the transmitter housing and the metal pipeline cannot be guaranteed, connect them using metal wires and then reliably ground them⑥ In order to avoid the influence of relative measurement of flow velocity, the flow control valve should be set at the bottom of the transmitter. For small-diameter transmitters, because the distance from the electrode center to the inlet end of the flowmeter is equivalent to several times the length of diameter D, there is no need to make rules for the upstream straight pipe. However, for larger diameter flowmeters, there should generally be a straight pipe section of 5D or more upstream, and a straight pipe section is generally not required for the bottom⑦ The address of the converter equipment should avoid strong AC and DC magnetic fields and vibrations, with an ambient temperature of -20-50 ℃, no corrosive gases, and a relative humidity not exceeding 80%