Electromagnetic flowmeter in use, signal interference problems how to solve?

Project Overview

　　Electromagnetic flowmeter in use signal interference problems, you can take the following measures to solve:

　　First, the correct grounding

　　Separate grounding: electromagnetic flowmeter must be properly grounded, and it is best to use a separate grounding method, avoid sharing grounding with other equipment to reduce grounding loop interference. Grounding resistance should be less than the specified value to ensure good grounding.

　　Equipotential grounding: In complex industrial environments, equipotential grounding can be used to connect the grounding of all related equipment together to form an equipotential surface to further reduce grounding loop interference.

　　Second, shielding measures

　　Cable shielding: the use of shielded cables can effectively reduce the interference of external electromagnetic fields on the flowmeter signal. Shielded cable shielding layer should be well grounded to ensure the shielding effect. You can choose a cable with a copper braid shielding layer, and the shielding layer and the flowmeter ground terminal connection.

　　Sensor shielding: In some strong electromagnetic field environment, sensor shielding can be used to reduce interference. Shield is usually made of metal materials, the sensor can be isolated from external electromagnetic fields.

　　Third, reasonable wiring and installation

　　Away from the source of interference: in the installation of electromagnetic flowmeter, should try to stay away from high-voltage power lines, transformers, motors and other sources of strong electromagnetic field interference. If it can not be avoided, you can take measures to increase the distance, set up shielding and other measures to reduce interference.

　　Standardised wiring: cable wiring should be carried out in strict accordance with the specifications, to avoid excessive improper interfaces and long-distance parallel release, in order to reduce electromagnetic interference.

　　Fourth, hardware and software filtering

　　Hardware filtering: In the electromagnetic flowmeter signal processing circuit to join the filter, can effectively remove high-frequency noise and interference signals. Common filters are low-pass filter, high-pass filter, band-pass filter.

　　Software filtering: the signal filtering process through the flowmeter's software algorithm can further improve the quality of the signal. Common software filtering methods are mean filter, median filter, Kalman filter and so on.

　　V. Other measures

　　Reduce the impact of earth current: by increasing the area of the earth electrode or changing the structure of the earth network and other measures, you can reduce the impact of earth current on the electromagnetic flowmeter.

　　Selection of suitable lining materials: the choice of lining materials should be combined with the nature of the fluid and environmental conditions, which is conducive to reducing the impact of fluid pulsation and improve the accuracy of measurement.

　　Regular maintenance and inspection: regular maintenance and inspection of the electromagnetic flowmeter to ensure its normal operation. The inspection includes whether the cable connection is good, whether the grounding is reliable, whether the sensor is damaged and so on.

　　In summary, to solve the electromagnetic flowmeter in use signal interference problems need to start from the grounding, shielding, wiring and installation, filtering and other measures and other aspects. By systematically analysing the nature of the interference and take appropriate measures to deal with, can effectively improve the measurement accuracy and stability of electromagnetic flowmeter.