Daily maintenance (1)
Only need to periodically check the instrument, check the environment around the instrument, remove the dirt, ensure that no water and other substances are inspected, check whether the wiring is good, check whether there is a new strong electromagnetic field device near the instrument or a new installed wire across the instrument. If the measuring medium is easy to contaminate the electrode or precipitate or scale in the measuring tube wall, it should be regularly cleaned and cleaned.
Folding fault finding
After the flowmeter starts to be put into operation or is put into operation for a period of time, it is found that the instrument is not working properly. First, check the external condition of the flowmeter, such as whether the power supply is good, whether the pipeline is leaking or is in a state of non-full pipe, whether there is air bubble in the pipe, whether the signal cable is Damage, converter output signal (ie rear position meter input loop) is open circuit. Remember to blindly disassemble the flowmeter.
Test equipment: one 500MΩ insulation resistance tester, one multimeter.
(1) When the pipeline is filled with medium, measure the resistance between terminals A, B and C with a multimeter. The resistance between A-C and B-C should be equal. If the difference is more than 1 time, there may be leakage of the electrode, condensation on the outer wall of the measuring tube or the junction box.
(2) In the case of lining drying, measure the insulation resistance between A-C and B-C with MΩ meter (should be greater than 200MΩ). Then use a multimeter to measure the resistance of the two electrodes in terminals A and B and the measuring tube (should be in short-circuit communication). If the insulation resistance is small, indicating that the electrode is leaking, the entire flowmeter should be returned to the factory for repair. If the insulation is reduced but there is still more than 50 MΩ and the inspection result of step (1) is normal, the outer wall of the measuring tube may be damp, and the inside of the outer casing may be dried by a hot air blower.
(3) Use a multimeter to measure the resistance between X and Y. If it exceeds 200 Ω, the excitation coil and its lead wire may be open or poorly connected. Remove the terminal block check.
(4) Check the insulation resistance between X, Y and C, which should be above 200 MΩ. If it is lowered, dry the inside of the casing with hot air. In actual operation, the decrease in coil insulation will result in increased measurement error and unstable instrument output signal.
(5) If it is determined that the sensor is faulty, please contact the manufacturer of the electromagnetic flowmeter. The general site cannot be solved and needs to be repaired by the manufacturer.
Gas turbine flowmeter and screwing vortex flowmeter measurement difference
Keywords: gas turbine flowmeter, Tianxin gas turbine flowmeter, gas gas turbine flowmeter
The gas turbine flowmeter has good repeatability and is the preferred flow meter for trade settlement. The gas swirling vortex flowmeter is generally repeatable.
The gas turbine flowmeter can obtain very high frequency signals with strong signal resolution. The frequency of the gas swirling vortex flowmeter is very low, and the smaller the diameter, the lower the signal resolution. The measurement error is to be measured.
The gas turbine flowmeter has a wide range, generally 40:1~20:1, and has a wide measuring range, which can be suitable for occasions with large flow changes. When natural gas is delivered, the flow changes are generally large and, therefore, are particularly suitable for natural gas measurements. The latter range is medium, generally 15:1 to 10:1, and the measurement range is slightly narrower. When measuring gas, it is more suitable for occasions where the flow rate does not change much.
In terms of seismic performance, gas turbine flowmeters have better resistance to pipeline vibration. The gas swirling vortex flowmeter is susceptible to pipeline vibration and should be taken care of when using it.
Compressed air flowmeter installation requirements
Keywords: compressed air flow meter, compressed air vortex flowmeter, air flowmeter
First, the compressed air vortex flowmeter installation requirements
1. The upstream of the compressed air vortex flowmeter should avoid installing the regulating valve or the semi-opening valve. The regulating valve or the semi-opening valve is installed after the downstream 8DN of the sensor.
2. The straight pipe section where the flowmeter is installed should be as close as possible to the sensor diameter. If it is not consistent, a pipe diameter slightly larger than the sensor diameter should be used, and the error should be ≤3% and not more than 5mm.
3. When the measured medium contains more impurities, the filter should be installed outside the length required for the straight pipe section upstream of the sensor.
4, the sensor should be avoided on the pipeline with mechanical vibration, and try to avoid strong electromagnetic field interference. When vibration cannot be avoided, consider adding a bracket to the straight pipe section about 2DN before and after the sensor.