Grounding resistance of electromagnetic flowmeter

The grounding resistance of the electromagnetic flowmeter is the potential difference between the electrode and the ground, that is, the voltage of the current passing through the electrode and entering the ground.

1. The role of the grounding resistance of the electromagnetic flowmeter

Electromagnetic flowmeter detects flow When the signal is generated, the electrode needs to be in contact with the liquid. At this time, a potential difference is formed between the electrode and the ground. The return circuit forms a loop (Potential Loop), which may cause noise interference and thus affect the accuracy and stability of the measurement. The purpose of a ground resistor is to eliminate loops by connecting the flowing liquid, all metal parts of the liquid measurement system, and the system's power supply through a common ground wire. In this way, during the measurement process, the potential difference only exists between the ground electrode and the ground, thereby eliminating the loop and greatly improving the measurement accuracy and stability of the electromagnetic flowmeter.

2. The voltage point for measuring the ground resistance

The ground resistance is usually measured at the interface of the electrode or inside the socket, as shown in the figure below. Normally, the electrode interface of the electromagnetic flowmeter enters the main body of the electromagnetic flowmeter through a large rocker, located between the main body and the liquid measurement system. The grounding resistance is measured between the electrode and the ground before entering the main body of the electromagnetic flowmeter. The potential difference between them is the potential difference between the electrodes before entering the main body of the electromagnetic flowmeter.

3. The influence of grounding resistance on the accuracy of electromagnetic flowmeter

The appropriate grounding resistance value has a great influence on the measurement accuracy of electromagnetic flowmeter. If the ground resistance value is too small and the current is too strong, serious thermal effects may occur, causing the temperature of the sensor to rise and affecting the accuracy and stability of the electromagnetic flowmeter. If the ground resistance value is too large, it will affect the sensitivity of the sensor, causing the voltage signal of the electromagnetic flowmeter to drop and the signal-to-noise ratio to become worse, thus affecting the measurement accuracy and stability. Therefore, the appropriate grounding resistance value needs to be selected according to the specific electromagnetic flowmeter model and usage environment.

The grounding resistance of the electromagnetic flowmeter is the potential difference between the electrode and the ground, that is, the voltage at which the current passes through the electrode and enters the ground. Ground resistance is mainly used to eliminate loops generated during electromagnetic flowmeter measurement and improve measurement accuracy and stability. The appropriate grounding resistance value has a significant impact on the accuracy and stability of the electromagnetic flowmeter.