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The characteristic of the sensor in a split-type electromagnetic flowmeter is that it is a device for measuring volumetric flow rate; a split-type electromagnetic flowmeter consists of two main components: the sensor and the flow rate converter. The main components are the measurement tube, electrodes, excitation coil, core and yoke, and housing. The measuring tube of the sensor is a short tube made of a non-magnetic alloy, lined with insulating material. The fluid to be measured must be a conductive liquid or slurry; it should not contain large amounts of ferromagnetic materials or bubbles. The appropriate pressure rating, lining material, electrode material, and instrumentation must be selected based on the fluid’s temperature, pressure, corrosiveness, wear resistance, and other characteristics. During the measurement process, it is not affected by the temperature, viscosity, density, or conductivity (within a certain range) of the medium being measured. After calibration using a liquid calibration device, it can be used to measure the flow rate of other conductive liquids; therefore, the proper installation of the sensor is extremely important. The following requirements should be met: Preferably, split-type electromagnetic flowmeter sensors require certain straight pipe sections upstream and downstream of the installation point, otherwise it will affect the measurement accuracy. If there is a reducer upstream of the sensor installation point, there should be a straight section with a constant diameter of at least 15D upstream of the sensor, and a straight section with a constant diameter of at least 5D downstream of it. If there is a flare pipe upstream of the sensor installation point, there should be a straight section with a constant diameter of at least 18D upstream of the sensor, and a straight section with a constant diameter of at least 5D downstream of it. If there is a 90° elbow or elbow fitting upstream of the sensor installation point, there should be a straight pipe section of equal diameter of at least 20D upstream of the sensor, and a straight pipe section of equal diameter of at least 5D downstream of it. If there are two 90° elbows on the same plane upstream of the sensor installation point, there should be a straight pipe section of equal diameter of at least 25D upstream of the sensor, and a straight pipe section of equal diameter of at least 5D downstream of it. If there are two 90° elbows on different planes upstream of the sensor installation point, there should be a straight pipe section of equal diameter of at least 40D upstream of the sensor, and a straight pipe section of equal diameter of at least 5D downstream of it. The flow control valve or pressure control valve should be installed at least 5D downstream of the sensor; if it must be installed upstream of the sensor, there should be a straight pipe section of equal diameter of at least 50D upstream of the sensor, and another straight pipe section of equal diameter of at least 5D downstream of it. Special attention: If a valve is installed at a location close upstream of the installation point of the split-type electromagnetic flowmeter sensor, constantly opening and closing this valve has a significant impact on the sensor’s service life, and can very easily cause damage to the sensor. Sensors should be installed as far as possible away from very long overhead pipelines; otherwise, over time, the sagging of the sensors can easily lead to leakage at the seal between the sensor and the flange. If installation is unavoidable, pipe fastening devices must be installed 2D distances upstream and downstream of the sensor. Precautions for installing split-type electromagnetic flowmeters The sensor of a split-type electromagnetic flowmeter should be installed vertically, with the fluid flowing from bottom to top, in order to ensure that solids and liquids are in a mixed state. The reason is that when there are solids in the medium (such as sediment, small stone particles, etc.), precipitation tends to occur. Additionally, when there are fish and weeds in the pipeline, the movement of these fish within the pipeline causes fluctuations in the output of the flow meter ； The back-and-forth movement of weeds hanging near the electrodes can also cause instability in the flow meter’s output. A metal filter is installed at the upstream inlet of the flow meter to prevent fish and weeds from entering the measurement tube. Improper piping setup of the split-type electromagnetic flowmeter to prevent negative pressure can result in negative pressure being generated inside the sensor. When the valves upstream and downstream of the flow meter are closed simultaneously, if the temperature of the fluid is higher than the ambient temperature, it will contract upon cooling, creating a risk of negative pressure within the pipe. Negative pressure causes the lining to separate from the metal conduit, resulting in electrode leakage. A negative pressure prevention valve is installed near the split-type electromagnetic flowmeter; the valve is opened to connect with atmospheric pressure, in order to prevent a negative pressure from forming inside the sensor. When a vertical pipe is connected downstream of a split-type electromagnetic flowmeter, and the flow is shut off or regulated using a valve upstream of the flow sensor, a negative pressure will be created inside the sensor’s measurement tube. To prevent negative pressure, backpressure must be applied or downstream valves must be used to regulate and shut off the flow. Split-type electromagnetic flowmeters require adequate maintenance space; large-diameter flowmeters are often installed in instrument wells, and appropriate space needs to be provided for the convenience of pipeline installation, wiring, inspection, and maintenance. For the convenience of observation, wiring, and maintenance, instruments should be installed at a certain height above the ground to facilitate cleaning and installation. Proper installation of the flow meter can achieve twice the result with half the effort, making flow measurement more accurate and reliable. I. To ensure the reliable and stable operation of intelligent electromagnetic transmitters, the following requirements should be taken into account when selecting the installation location: ⑴ Try to avoid ferromagnetic objects and devices with strong electromagnetic fields (such as large motors and large transformers), so as to prevent the magnetic field from affecting the working magnetic field of the sensor and the flow signal. ⑵It should be installed in a dry and well-ventilated area; it is not suitable for installation in damp places where water tends to accumulate. ⑶Exposure to sunlight and rain should be avoided as much as possible, as well as environments with a temperature above 60°C and a relative humidity greater than 95%. ⑷Choose a location that is easy to maintain and convenient for access. ⑸The flow meter should be installed at the rear end of the water pump; it must not be installed on the suction side ； The valve should be installed on the downstream side of the flow. II. To ensure accurate measurements, the following requirements should be taken into account when selecting the location on the pipeline: ⑴ The sensor of a split-type electromagnetic flowmeter can be installed on straight pipelines, as well as on horizontal or inclined pipelines, provided that the line connecting the two electrodes remains horizontal. ⑵The medium should flow fully within the pipe at the installation location, to prevent gas from accumulating in the pipe or adhering to the electrodes. ⑶For liquid-solid two-phase fluids, it is best to use a vertical installation to ensure even wear of the sensor lining and extend its service life. ⑷When the medium in the pipeline at the flow meter installation location is not sufficient, the method of raising the pipeline section behind the flow meter can be used to ensure that the pipeline is filled with medium. It is strictly prohibited to install flow meters at the highest point of the pipeline or at the outlet. 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