Anti-interference problem of electromagnetic flowmeter (2)

1.1 Internal disturbance

 The disturbance sources within the system can be divided into:

 (1) Power disturbance. Power disturbance is mainly immersed into the system from the power supply and power leads.

 (2) Ground wire disturbance. Ground disturbance is caused by the sharing of a ground wire in the system. When the current of each part of the circuit in the system flows through the common ground wire, a voltage drop will occur on the ground wire, forming noise that affects each other.

(3) Coupling disturbance of signal channel. If the signal requires a long transmission line, the signal is simply disturbed during the transmission process, resulting in the distortion or distortion of the transmitted signal. The main disturbance is the electromagnetic induction disturbance of the transmission line by the electromagnetic field around the transmission line: Or when two or more signal lines with different transmission signal strengths are close to each other, the inter-line interference formed by the distributed capacitance and mutual inductance between the lines is the crosstalk between the transmission lines.