Points to Be Noted in Electromagnetic Flowmeter Engineering Application 2

5. The electromagnetic flow transmitter should be installed in a dry and ventilated place indoors. Avoid installing it in a place with high ambient temperature. It should not be subject to strong vibration. Try to avoid equipment with strong magnetic fields, such as large motors, transformers, etc. In the case of corrosive gas, the installation site is convenient for maintenance, which is the environmental condition to ensure the normal operation of the transmitter.

6. In order to ensure that the measuring tube of the electromagnetic flow transmitter is filled with the measured medium, the variator is best installed vertically with the flow direction from bottom to top, especially for liquid-solid two-phase flow, it must be installed vertically. If only horizontal installation is allowed on site, you must ensure that the two electrodes are at the same level.

7. Valves and bypasses should be installed at both ends of the electromagnetic flow transmitter.

8. The AC potential of several millivolts measured by the electrodes of the electromagnetic flow transmitter is based on the liquid potential in the transmitter. In order to stabilize the liquid potential and keep the transmitter and fluid at the same potential, to ensure stable measurement, the transmitter shell and the metal tube should have good grounding, the converter shell should also be grounded, and the grounding resistance should not be greater than 10 Ohm, cannot be shared with the ground wire of other electrical equipment. If it is not guaranteed that the transmitter housing is in good contact with the metal pipe, use metal wires to connect them and then ground them reliably.

9. In order to avoid disturbing the signal, the signal between the transmitter and the converter must be transmitted with shielded wires. It is not allowed to put the signal cable and the power cable in parallel in the same cable steel tube. The length of the signal cable should generally not exceed 30m.

10. The installation site of the converter should avoid strong AC and DC magnetic fields and vibrations, the ambient temperature is -20~50℃, and it must not contain corrosive gases, and the relative humidity is not more than 80%.

11. In order to ensure the normal operation of the electromagnetic flowmeter and reduce the measurement error, the electromagnetic flowmeter should meet certain straight pipe requirements before and after. According to the test standard requirements of JJG 1033-2007 "Electromagnetic Flowmeter Verification Regulations", usually the front straight pipe section should reach 10D, and the rear straight pipe section should be 5D.

The above information is provided by flow instrument factory.

You can also find part 1 in our previous articles.