External interference factors of electromagnetic water meter

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  External interference factors of electromagnetic water meter

  Because the electromagnetic water meter has strict specification relativity and high accuracy, the electromagnetic water meter is closely related to the system software. It can analyze the tap water condition in real time and is widely used in the municipal field. Based on Faraday's law of electromagnetic induction, the electromagnetic water meter is often disturbed by external causes, resulting in inaccurate measurement. The following are several factors that cause interference.

  (1) Pipeline stray current

  Generally, electromagnetic intelligent water meters have good grounding protection. Generally, the grounding resistance should be less than 100Q. Do not share grounding with other motors and appliances. Sometimes the environmental conditions are good and the electromagnetic flowmeter can work normally without grounding. Here, we suggest that the user should be grounded even so. Sometimes, although the electromagnetic flowmeter is well grounded, the stray current of the pipeline is too strong, which will affect the normal measurement of the electromagnetic intelligent water meter. At this time, the electromagnetic flow sensor must be electrically isolated from the pipeline.

  (2) Electrostatic and electromagnetic interference

  Static electricity and electromagnetic waves will be introduced through the signal line between the electromagnetic intelligent water meter sensor and the converter. Generally, if the signal line is well shielded, such as shielded cable, the cable can be prevented and prevented by placing it in the protective iron pipe. However, there are also examples of ineffective prevention and control of strong electromagnetic wave. At this time, the converter can be moved near the sensor, the connected signal cable can be shortened, or an all-in-one instrument without external cable can be used.

  (3) Magnetic field interference

  Usually only take electromagnetic flow sensor away from strong magnetic field source. The ability of electromagnetic intelligent water meter to resist magnetic field varies depending on the structural design of the sensor. For example, the protective shell of the sensor excitation coil is made of non-magnetic materials (such as aluminum and plastic), and the ability to resist the influence of magnetic field is weak, while that made of steel is strong.