Magnetic flowmeter online calibration method

When the electromagnetic flowmeter is shipped from the factory, its accuracy is already over-calibrated. However, it is suitable for people who use it in the field. Due to the environmental conditions, fluid characteristics, and many faults caused by the damage of the instrument itself, it is necessary to calibrate the electromagnetic flowmeter used for a long time. Here is a look at the electromagnetic flowmeter. Online calibration method.

1. The safety insulation test of the electromagnetic flowmeter excitation coil should be more than 20MΩ.

2. The copper resistance test of the electromagnetic flowmeter excitation coil should be the same as the original factory value (when the ambient temperature is the same).

3. The resistance of the electromagnetic flowmeter sensor electrode to ground is tested. If the resistance value is between 2 and 20kf, and there is a phenomenon of charge and discharge, the resistances of the two electrodes are similar, and it is considered as good.

4. Test the excitation current of the electromagnetic flowmeter converter and observe the values ​​of its output and the original current of the converter. The error does not exceed 0.25mA.

5. Test the analog output and frequency output of the electromagnetic flowmeter converter to observe its linear variation and calculate its maximum linearity error, which should not exceed ±0.5%.

6. Electromagnetic flowmeters with a DN 1200mm or more should be tested at the push-level NB with a current error of no more than 12mA.