Electromagnetic flowmeter is a flow measuring instrument that works based on the law of magnetic induction. The magnetic flowmeter consists of a transmitter and a converter. The electromagnetic flow transmitter converts the change of the flow into the change of the induced electric potential. The converter amplifies the weak induced electric potential and converts it into a unified standard signal output for remote indication, recording, accumulation and adjustment. It can measure the volume flow of a liquid or a mixture of liquid and solid with a certain conductivity. It is often used to detect the flow of acids, alkalis, salts, and liquids containing solid particles. This is its superiority to other flow meters.
Electromagnetic flowmeter use and maintenance
1. The magnetic flowmeter sensor should be installed in a place where the pipe is filled with liquid at any time to avoid the illusion that the pointer is not at the zero position when there is no liquid in the pipe. Generally, it should be installed vertically to prevent errors caused by bubbles formed when the liquid flows through the electrode.
2. The signal of the magnetic flowmeter is relatively weak, generally 2.5-8mV, especially when the flow is very small, only a few microvolts, so pay special attention to the influence of external interference on the measurement accuracy when using it. Therefore, the outside of the electromagnetic flowmeter, the shielding wire, the measuring wire, and the pipes at both ends of the electromagnetic flowmeter must be connected to a single grounding point to avoid additional interference due to unequal ground potentials.
3. The electromagnetic flowmeter should be installed far away from all magnetic sources, and vibration is not allowed.
4. When using the power supply, the electromagnetic flowmeter and the flow totalizer need to use the same phase line to avoid a 120° phase difference between the detection and feedback signals, which will cause the meter to fail to work normally.
5. The deposited scale layer on the inner wall of the electromagnetic flowmeter tube should be cleaned regularly to prevent short circuit of the electrode or even failure to measure the flow rate. Always keep the insulating lining of the pipe of the primary meter in good condition to avoid corrosion of acid, alkali, salt, etc., which may cause the meter to fail to detect.
6. Perform periodic visual inspection of the instrument, check the environment around the instrument, sweep away dust and dirt, and ensure that no water and other substances enter.
7. Check whether the wiring is in good condition, and check whether there is a newly installed strong electromagnetic field device near the meter or a newly installed wire across the meter.