Interpretation of electromagnetic flowmeter quality judgment

The electromagnetic flow meter is a flow meter for measuring flow, which has certain applications in many industries. The electromagnetic flowmeter has many advantages such as low pressure loss, wide measuring range, good stability and high measuring accuracy. I believe many people don\'t know how to judge the quality of electromagnetic flowmeters.

1. The measurement of the resistance value of the pickup coil is mainly to determine whether there is a short circuit between the turns of the pickup coil. The resistance value of the exciter coil should generally be 30 ohms to 170 ohms. If the resistance value is the same as that recorded at the factory, we believe that the coil is good, then indirectly judge that the magnetic field strength of the electromagnetic flowmeter sensor has not changed.
2. Measure the insulation resistance of the coil exquote against ground (measuring line number \"1\" and \"7\" or \"8\") to determine if the sensor is wet. The resistor value should be greamore than 20 megohms.
3. Measure the contact resistance value between the electrode and the liquid and indirectly evaluate the state of the electrode and the surface of the coating layer in the component. For example, the presence of a deposition layer attached to the surface of the electrode and the coating layer depends on whether the deposition layer is conductive or insulating. The resistance value between them should be 1KΩ~1MΩ, and the resistance values ​​of wire numbers \"1\" and \"2\" and \"1\" and \"3\" should be symmetrical.
4. Close the valve on the line, check the zero point of the electromagnetic flowmeter if there is no liquid flow and remember that it is a full liquid.
5. Use the GS8 calibration instrument to detect the converter output current. Whenthe given flow rate is 0, the output current of the flowmeter must be: 4.00 mA; when the given rate is 100%, the output current should be: 20.00 mA. The error of output current t value should be guaranteed within about 1.5%.
6. Test the value of the excitation current between terminals \"7\" and \"8\" of the converter. The positive and negative values ​​of the excitation current must be within the range of 137 (5%) mA. Pay attention to the influence of the external environment of the magmeter on the test results during the test: If the excitation line and the signal line are laid in the same pipeline, the excitation line and the signal are parallel to the high voltage cable, and there are large transformers or motors around, etc. The influence of the operating precision is evaluated. This evaluation mainly uses the visual inspection method to observe whether the electromagnetic flowmeter in operationionization shows sudden changes or fluctuations, and roughly judges whether the electromagnetic flow meter is disturbed by electromagnetic waves or other spurious waves, or whether there is a problem in the pipeline. bubble.

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