The accuracy of the electromagnetic flowmeter has been measured by the measuring line when it leaves the factory. However, in the field, due to natural environmental conditions, fluid characteristics and instrumentation itself such as damaged components and other common failures in instrumentation and operation, the flowmeter after long-term use must be carried out once on a regular basis. Correction.
Because the sensor of the electromagnetic flowmeter is installed on the pipeline, it is difficult to remove it and send it to the measurement line for inspection. At the current stage, within the range of the flowmeter, China and some of the large-mouth flowmeters have not conducted on-line testing under field conditions. Technical specifications and other regulatory documents. In order to ensure the accuracy and long-term use of electromagnetic flowmeters after repairing common faults and
Probe domestic high current measuring needle 150 head diameter 3.0 thread
The accuracy of the electromagnetic flowmeter has been measured by the measuring line when it leaves the factory. However, in the field, due to natural environmental conditions, fluid characteristics and instrumentation itself such as damaged components and other common failures in instrumentation and operation, the flowmeter after long-term use must be carried out once on a regular basis. Correction.
Because the sensor of the electromagnetic flowmeter is installed on the pipeline, it is difficult to remove it and send it to the measurement line for inspection. At the current stage, within the range of the flowmeter, China and some of the large-mouth flowmeters do not have on-line testing Technical specifications and other regulatory documents.
In order to ensure the accuracy and credibility of electromagnetic flowmeters after repairing common faults and after long-term use, without affecting the normal production and production, the following content online correction methods are released:
1. Check the excitation current of the converter of the electromagnetic flowmeter and observe the value of the output and the original current of the converter. The deviation does not exceed ± 0.25 mA.
2. For electromagnetic flowmeters with a diameter of DN1200mm or more, the propulsion level Nb should be detected, and the deviation of the current amount does not exceed 13 mA. 3. The safety insulation test for the excitation coil of the electromagnetic flowmeter should exceed 22MΩ.
4. Measure the resistance of the electrode of the electromagnetic flowmeter to ground. If the resistance value is between 2 and 22kf, and it is accompanied by the charge and discharge phenomenon, the resistance of the two electrodes is similar.
5. Test the analog input and output and frequency output of the electromagnetic flowmeter converter, observe its linear change, and calculate its maximum linear deviation, which should not exceed ± 0.6%.
6. The copper resistance test of the excitation coil of the electromagnetic flowmeter should be the same as the original factory value (when the ambient temperature is the same).