Magnetostrictive level gauge maintenance example

1. The magnetostrictive level gauge shows fluctuations during the day, but the night shift is normal.

[Fault check] The night shift voltage will be high, is the power supply abnormal? No problems were found in the inspection of the power supply, sensors, and transmitters. Later, I saw that there was a welding machine at work more than 30 meters away from the meter. If you look at the arc together with electric welding, the liquid level display will fluctuate.

[Troubleshooting] After the electric welder tried to move the ground wire of the welding machine, the magnetostrictive level gauge showed normal recovery.

[Maintenance Summary] This example is a fault caused by electromagnetic interference. The welder welds in several places, too lazy to pull the ground to run around, and the electric welding ground wire is clamped on the support frame of the instrument cable tray, which causes interference to the instrument. To solve the problem of instrument interference, please read the article "Measurement and Control Instrumentation Anti-interference Measures" of Changhui Instrument Network.

2, magnetostrictive level gauge, showing fluctuations and then running the maximum, and finally did not show.

[Fault check] Check that the power supply is normal. The transmitter that displays the abnormality has been powered by a separate power supply, but the output signal is still not normal. When it is not displayed, check that the module of the transmitter is damaged.

[Troubleshooting] Replace the module emergency. Contact the magnetostrictive level gauge supplier to help solve the problem.

[Maintenance Summary] This case is a quality problem of the magnetostrictive level gauge because there are many identical faults in the batch of instruments on the site, and the final result is that the transmitter module burns out. No such failure occurred after the product was replaced.

3, magnetostrictive level gauge, over-range alarm, current up to 21mA.

[Fault check] The power supply and transmitter are normal. Check that the float position is too low below the normal zero when the empty can is found.

[Troubleshooting] Add a stainless steel sleeve to the bottom of the float and return to normal after resetting the range.

[Maintenance Summary] In this case, the difference between the float and the normal zero is too large when there is no liquid level. When the float is at the bottom of the measuring rod, the circular magnetic field of the float and the lower end of the magnetostrictive wire in the measuring rod are insensitive, thus appearing. False alarm phenomenon.