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This post was last edited by zhengpeichun on 2018-4-10 at 15:53. An electromagnetic flowmeter consists of a sensor and a converter, and is an inductive instrument used to measure the volumetric flow rate of conductive media. An electromagnetic flowmeter operates based on Faraday’s law of electromagnetic induction. To ensure the proper use of the product, the following 6 points need to be taken into consideration when purchasing an electromagnetic flowmeter: First, attention must be paid to the choice of installation type. 1. Integrated type: In this configuration, the sensing part and the conversion part of the electromagnetic flowmeter are combined into one unit, and the advantage of this is ease of installation. 2. Separate type: The sensing part of the flow meter is installed on the pipeline to be measured, while the conversion part is installed in a room where it is easy to operate. Suitable for locations with poor on-site conditions (but its separation distance should be less than 30m). II. Attention must be paid to the selection of the grounding ring. If the pipeline connecting the instrument is insulating with respect to the medium being measured, a grounding ring must be used. III. It is essential to pay attention to the selection of ball valves. In applications where the flow rate of the fluid in the pipeline must not be interrupted, and where it is necessary to prevent the medium from leaking, ball valves need to be installed. For flow meters where it is permissible to interrupt the flow during installation or removal (or where such operations do not affect the operation of the pipeline), there is no need to install a ball valve; the electromagnetic flow meter can be directly mounted on the flanged stub. IV. Attention must be paid to the key points during installation. 1. The axis of the electrode must remain approximately horizontal. 2. Ensure that the measuring tube is always filled. 3. Ensure sufficient space is available near the pipe flange for installing bolts and nuts. 4. Pipeline supports should be provided in the sections equipped with flow meters to reduce vibration during pipeline operation. 5. Strong electromagnetic fields should be avoided near the electromagnetic flowmeter. 6. For long pipelines, control valves and isolation valves should be installed downstream of the flow meter. 7. In the case of an \"open inlet or outlet\" condition, instruments should be installed in the lower section of the pipeline. 8. Based on the electrode axis, the straight inlet section must be 5 times or more the diameter of the measuring tube, while the outlet pipe must be 2 times or more the diameter of the measuring tube. V. Attention must be paid to the grounding of electromagnetic flowmeters. The sensor should have a proper separate grounding wire (with a copper core of a cross-sectional area of ≥16 mm2), and its grounding resistance should be <10 ohms ； If the pipe connecting the sensor is coated with an insulating layer or is a non-metallic pipe, grounding rings should be installed on both sides of the sensor (the cross-sectional area of the copper core of the grounding wire should be ≥16 mm2). VI. Attention must be paid to the connections of cables and electrical components. For separate connection cables (for signal transmission and excitation), the shorter they are, the better, both to reduce interference and save costs. Generally, it is necessary to take into account the limitations imposed by the conductivity of the dielectric, the cross-sectional area of the excitation cable, and the specifications of the signal cable (cores, layers, shielding).