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7 ways to correctly judge the good and bad of intelligent electromagnetic flowmeter

(1) Measure the resistance value of the excitation coil to determine whether the excitation coil has a turn-to-turn short circuit (resistance between line numbers 7 and 8), and the resistance value should be between 30 ohms and 170 ohms. If the resistance is the same as the factory record, the coil is considered to be good, and the magnetic field strength of the smart electromagnetic flowmeter sensor is indirectly evaluated.
(2) Measure the insulation resistance of the excitation coil to ground (line No. 1 and 7 or 8) to determine whether the sensor is damp, and the resistance value should be greater than 20 megohms.
(3) Measure the contact resistance between the electrode and the liquid (line numbers 1 and 2 and 1 and 3), and indirectly evaluate the general condition of the surface of the electrode and the lining layer. If the electrode surface and the backing layer are attached to the deposited layer, whether the deposited layer is electrically conductive or insulative. The resistance between them should be between 1 kohm and 1 megohm, and the resistance values of line numbers 1 and 2 and 1 and 3 should be roughly symmetrical.
(4) Close the valve on the pipeline and check the zero point of the whole machine when the intelligent electromagnetic flowmeter is full of liquid and the liquid is not flowing. Make appropriate adjustments as appropriate.
(5) Check the insulation resistance of each core wire of the signal cable and the excitation cable to check whether the shielding layer is intact.
(6) Test the output current of the converter using the GS8 calibration instrument. When zero flow is given, the output current should be: 4.00 mA; when given 100% flow, the output current should be: 20.00 mA. The error of the output current value should be better than 1.5%.
(7) Test the excitation current value (between converter terminals 7 and 8). The positive and negative excitation current should be within the specified range, which is approximately 137 (5%) mA.
During the installation and use of the instrument, it is necessary to pay close attention to the influence of the external environment of the intelligent electromagnetic flowmeter: for example, the excitation line and the signal line are laid in the same pipeline, the excitation line and the signal line are parallel with the high-voltage cable, and there are large transformers or motors around. The factors affect the operation accuracy of the intelligent electromagnetic flowmeter. This evaluation mainly uses the visual method to observe whether the intelligent electromagnetic flowmeter in operation has sudden or fluctuating conditions. It is generally judged whether the intelligent electromagnetic flowmeter is subjected to electromagnetic waves or other spurs. Wave interference or the presence of air bubbles in the pipe. We only provide the ideal external environment for the stable operation of the instrument to the maximum extent, so that the instrument can measure the accurate data required in our production.

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