【 Summary Description 】 The sensor of the split type electromagnetic flowmeter should be installed vertically, and the fluid should flow from bottom to top to meet the mixing state of solid and liquid. The reason is that solid objects (such as sediment, small stone particles, etc.) in the medium are prone to precipitation. In addition, if there are fish and weeds in the pipeline, the movement of fish in the pipeline will cause the output of the flowmeter to oscillate back and forth; The back and forth swing of weeds hanging near the electrode can also cause instability in the output of the flowmeter. Install a metal filter at the upstream inlet of the flowmeter to block fish and weeds from entering the measuring tube.

1、 Precautions for installation of split type electromagnetic flowmeter

1. The sensor of the split type electromagnetic flowmeter should be installed vertically, and the fluid should flow from bottom to top to meet the mixing state of solid and liquid. The reason is that solid objects (such as sediment, small stone particles, etc.) in the medium are prone to occur

The situation of sedimentation. In addition, if there are fish and weeds in the pipeline, the movement of fish in the pipeline will cause the output of the flowmeter to oscillate back and forth; The back and forth swing of weeds hanging near the electrode can also cause instability in the output of the flowmeter. Install a metal filter at the upstream inlet of the flowmeter to block fish and weeds from entering the measuring tube.

2. Improper installation and operation of the pipeline to prevent negative pressure in the split type electromagnetic flowmeter may cause negative pressure to be generated inside the sensor. When the valves upstream and downstream of the flowmeter are closed simultaneously, if the temperature of the fluid is higher than the air temperature, it will shrink after cooling, which poses a risk of forming negative pressure inside the pipe. Negative pressure causes the lining to peel off from the metal conduit, resulting in electrode leakage.

3. Add a negative pressure prevention valve near the split type electromagnetic flowmeter, open the valve to connect to atmospheric pressure to prevent negative pressure from being generated inside the sensor. When a vertical pipeline is connected downstream of a split type electromagnetic flowmeter, if the upstream valve of the flow sensor is used to close or adjust the flow rate, negative pressure will be formed inside the sensor measuring tube. To prevent negative pressure, it is necessary to add back pressure or use downstream valves to regulate and close the flow rate.

4. Proper maintenance space is required for split type electromagnetic flow meters. Large caliber flow meters are often installed in instrument wells, and for the convenience of pipeline installation, wiring, inspection, and maintenance, appropriate space needs to be left. For the convenience of observation, wiring, and maintenance, instrument installation should be at a certain height from the ground for easy cleaning and installation.

2、 Troubleshooting of Split Electromagnetic Flow Meter

The split type electromagnetic flowmeter may experience inaccurate measurements due to various malfunctions during operation. Generally, the malfunctions caused by electromagnetic flowmeters during operation can be divided into two categories. One type is caused by the malfunction of the flowmeter itself or damage to its components; One type of fault is caused by changes in external conditions, such as unstable output, countless flows, excessive errors, etc.

(1) Unstable output:

1. Unstable flow field; 2. The liquid detected by the sensor contains gas and large solid blocks; 3. Electrical connection virtual connection; 4. Poor grounding; 5. Solution to electrode leakage: 1. Modify the pipeline or install fake sensors; 2. Normal phenomenon; 3. Check the wiring and connect the wires properly; 4. Connect the ground wire properly; 5. Repair the sensor.

(2) Liquid flow without output:

1. Connect the two core wires of the signal transmission cable between the converter in reverse; 2. The power supply is not connected or has poor contact; 3. There is leakage in the sensor instrument pipeline, housing, and end face. Solution: 1. Inverted wire head; 2. Connect the power supply and maintain good contact; 3. Repair the sensor.

(3) Liquid does not flow but has output:

1. There is an open circuit in the signal transmission cable connection with the converter; 2. Signal cable to electrode connection open circuit; 3. Surface contamination or deposition of insulation layer on the electrode; 4. Poor grounding or open circuit. Solution: 1. Connect the cable properly; 2. Open the sensor and reconnect it; 3. Clean the surface of the electrode; 4. Connect the ground wire properly.

(4) Excessive error:

1. Zero point too high; 2. Not completely filled with liquid; 3. Excessive distortion of the power supply; 4. Poor grounding. Solution: 1. Adjust the zero point again; 2. Improve pipeline conditions, sensors are always filled with liquid; 3. Improve power supply conditions to meet normal working conditions; 4. Connect the ground wire properly.