Separate electromagnetic flowmeter installation points

1. The sensor of the split-type electromagnetic flowmeter should be installed vertically, and the fluid should flow from bottom to top, so as to meet the mixed state of solid and liquid.The reason is that there are solids in the medium (sand, small stone particles, etc.) easy to precipitate the situation.In addition, if there are fish and weeds in the pipeline, the fish swimming in the pipeline will cause the output of the flowmeter to swing back and forth.The back and forth of weeds hanging near the electrodes can also cause instability in the flowmeter output.A metal strainer shall be installed at the upstream entrance of the flowmeter to prevent fish and weeds from entering the measuring tube.

2. Separate electromagnetic flowmeter can prevent negative pressure generated in the sensor due to improper pipeline setting and operation.Close both upstream and downstream valves at the same time if the fluid temperature is higher than air temperature.Shrinkage after cooling, so that the pressure inside the tube has the danger of forming negative pressure.The negative pressure causes the lining to peel off from the metal conduit, causing the electrode to leak.

3. Add a negative pressure prevention valve near the split solenoid flow meter and open the valve to connect the atmospheric pressure to prevent negative pressure in the sensor.When the downstream of the split electromagnetic flowmeter is connected with a vertical pipe, if the upstream valve of the flow sensor is used to close or regulate the flow, negative pressure will be formed in the sensor measurement tube.To prevent negative pressure, apply back pressure or use downstream valves to regulate and close flow.

4. Proper maintenance space for split electromagnetic flowmeter. Large-diameter flowmeter is usually installed in instrument well, so appropriate space should be left for convenience of pipeline installation, wiring, inspection and maintenance.For the convenience of observation, connection and maintenance, the instrument should be installed at a certain height from the ground, so as to facilitate cleaning and installation.

Two, split type electromagnetic flowmeter troubleshooting

In the operation of the split type electromagnetic flowmeter due to various faults will cause the phenomenon of inaccurate measurement, generally in the operation of the electromagnetic flowmeter faults may be divided into two categories.One is the fault of the flowmeter itself and the fault caused by component damage;One is the failure caused by the change of external conditions, such as unstable output, numerous flows, excessive error, etc.

(1) Output instability:

1. Unstable flow field;2. The liquid passing through the sensor contains gas and large solid blocks;3. Virtual connection of electrical connection;4. Poor grounding;5. Solution to electrode leakage: 1. Modify the pipeline or install false sensors; 2.2. Normal phenomena;3. Check the wiring and connect the wires well;4. Connect the ground wire;5. Repair sensors.

(2) No output of liquid flow:

1. The two core wires of the signal transmission cable between the converter and it are connected inversely;2. The power supply is not connected or has bad contact;3. Leakage occurs in the pipeline, housing and end face of the sensor instrument.Solutions: 1. Inverted thread;2. Connect the power and keep good contact;3. Repair sensors.

(3) The liquid does not flow and has output:

1. The signal transmission cable between the converter and it is disconnected;2. Disconnect the signal cable from the electrode;3. Fouling or deposition of insulating layer on electrode surface;4. Poor grounding or broken circuit.Solution: 1, connect the cable;2. Turn on the sensor and reconnect;3. Scrub the electrode surface;4. Connect the ground wire.

(4) Excessive error:

1. The zero point is too high;2. Not fully filled with liquid;3. Excessive distortion of power supply;4. Poor grounding.Solution: 1. Readjust zero point; 2.2. Improve the pipeline conditions, and the sensor is always filled with liquid;3. Improve the power supply conditions to meet the normal working conditions;4. Connect the ground wire.

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