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13 tips for the installation of electromagnetic flowmeters

When electromagnetic flowmeters are widely used in many industries, they mainly use the Faraday electromagnetic induction principle. They are composed of a flow sensor and a transmitter. They are suitable for measuring the volumetric flow of conductive liquids and slurries in closed pipes, such as clean water. Sewage, various acid and alkali salt solutions, mud, pulp, pulp and liquids in food. The main components of the electromagnetic flowmeter sensor are: measuring tube, electrode, excitation coil, iron core and yoke housing. It is mainly used to measure the volumetric flow in conductive liquids and slurries in closed pipes. It includes highly corrosive liquids such as acids, bases, and salts. The product is widely used in petroleum, chemical, metallurgy, textile, food, pharmaceutical, paper and other industries as well as environmental protection, municipal management, water conservancy construction and other fields. The electromagnetic flowmeter converter core uses a high speed central processor. The calculation speed is very fast, the precision is high, and the measurement performance is reliable. The converter circuit has an input impedance of up to 1015 ohms and a common mode rejection ratio better than 100 db. It is better than 90 db for external interference and 60 Hz/50 Hz interference suppression, and can measure fluid conductivity of lower conductivity. The sensor adopts non-uniform magnetic field technology and special magnetic circuit structure, the magnetic field is stable and reliable, and the large size is reduced, the repetition is repeated, and the flowmeter is characterized by small flow.

Electromagnetic flowmeter installation should pay attention to the following 13 items:
1. It can be installed horizontally, vertically and obliquely, but it is necessary to ensure that the measuring tube is coaxial with the process pipe and that the measuring tube is always filled with liquid.
2. Note that the flow direction on the flow meter is consistent with the actual flow direction of the fluid;
3. Keep away from strong magnetic field equipment.
4. The measuring tube must be completely filled with the medium at all times. Only when the tube is full, can the accurate measurement be obtained. For the partial filling of the tube, the installation method similar to the anti-valve valve should be used. Do not install it at the low point of Zui. Prevent solids from collecting, and, in order to prevent vacuum, avoid installing the sensor at the inlet end of the pump;
5. When installing, make sure there is enough space near the pipe flange; there should be a certain straight pipe section upstream of the flowmeter sensor, generally 5D~10D. <br 6. The pipes on both sides of the flowmeter should be firmly supported, and should not be installed in places with strong vibration;
7. The measuring tube, the outer casing, the shield wire of the lead wire, and the pipe at both ends of the sensor must be reliably grounded, and must not be shared with the grounding of other electrical equipment. This is the special installation requirement of our three-meter electromagnetic flowmeter.
8. For easy installation, for large-size instruments with DN>200, telescopic tubes can be used to allow axial displacement of the mating flanges;
9. From the axis of the electrode, the length of the short straight pipe section of the upstream Zui is 5DN, and the length of the short straight pipe section of the downstream Zui is 2DN (DN is the inner diameter of the pipe);
10. For the split type intelligent electromagnetic flowmeter, the signal converter (and the power booster) should be installed as close as possible to the sensor. The shielded cable should be used as the double-shielded cable, and the signal converter should not be used. (or power booster) directly exposed to the sun, if necessary, can be installed with a sun shield;
11. For the spiral or spiral flow of the fluid, lengthen the upper and lower straight pipe sections and install the flow straightener;
12. In order to make the instrument work reliably and improve the measurement accuracy, without interference from external parasitic potential, the sensor should have a good separate grounding wire and grounding resistance.
13. Avoid strong vibration and strong corrosive places.

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