Common Faults and Solutions of Radar Level Meter

Radar level meters are widely used in the level measurement of high-temperature, high-pressure, flammable, explosive, and condensable media. This is inseparable from the advantages of radar level meters, such as simple structure, convenient installation, easy maintenance, and corrosion resistance. Nevertheless, due to the influence of improper selection, installation, and use, various faults and problems often occur during the use of radar level meters. In order to avoid affecting production and help instrument users better use radar level meters, this article briefly describes the common faults and treatments of radar level meters as follows.

High frequency ultrasonic radar level meter

1. Failures and treatments caused by instrument problems

　　If the meter measures abnormally, and inspection shows that the antenna is in good condition and installation and there are no obstacles inside the tank, it can be basically determined that the cause of the fault is the meter itself.

　　The more common ones are the following:

　　1. Instrument software or hardware failure. Upgrade the software, replace the instrument, or return the instrument for processing.

　　2. The current signal is greater than 22mA or 0mA. This fault is mostly caused by damage to electronic components. Solution: Replace the instrument in time or send it to the factory for repair.

　　3. 4-20mA signal is unstable. This fault is mostly caused by level fluctuation. Solution: Set a suitable integration time by adjusting the module or PACTware software.

　　4. 4-20mA signal is lost. This fault is mostly caused by incorrect wiring of the power supply, no power connection, or the power supply voltage is too low or the load resistance is too high.

　　Solution: Check the wiring to see if the power supply is reliably connected and correct the installation wiring diagram; check if the cable is disconnected and the fuse is burned out. If there is any cable breakage, repair it in time; if the voltage is too low or the load resistance is too high, pay attention to check and correct it.

2. There are false echoes in the radar level meter with bypass pipe

　　Cause of the failure: Because there are burrs, welding slag, welding seals and attached impurities on the wall of the bypass pipe, there are false echo signals that can be detected, which affect the detection of the real echo signal and cause the radar level meter to display a false liquid level.

　　Solution: Using computer software to store and eliminate false echoes is only a temporary solution. To completely solve the problem of false echoes and false liquid levels in radar level gauges, the bypass pipe should be cleaned and frosted. And pay attention to purchasing radar level gauges with relatively good quality to minimize measurement failures caused by such problems.

3. The instrument circuit fails due to poor sealing

　　Cause of failure: Most instrument circuit parts fail because the cable inlet and instrument cover are not tightly sealed, causing rain or other liquids, dust, humid gases, etc. to enter the instrument.

　　Solution: Therefore, when purchasing, you must give priority to radar level meters with better sealing performance. At the same time, you should pay attention to correct installation. If necessary, you can install a protective cover for the instrument to seal the entire instrument.

4. Antenna scarring affects the accurate measurement of radar level meter

　　Fault phenomenon: Hanging materials with very small dielectric constant have no effect on measurement in dry state, while hanging materials with very high dielectric constant have a great influence on measurement.

　　Solution: At this time, the antenna scarring can be eliminated by blowing with compressed air or flushing with clean water, or by regularly cleaning the scarring with an acidic cleaning solution (but it should be noted that measurements cannot be performed during the cleaning period).

5. Radar level meter antenna condenses or freezes in winter

　　Solution: In addition to regular inspection and cleaning, it is recommended to install insulation and heating devices on the outside of the radar level gauge to keep the temperature near the tank mouth basically constant.

6. Establish a sound daily maintenance system

　　In the process of using the radar level meter, in addition to timely handling of faults, daily correct maintenance is also essential. Generally speaking, in the daily use and maintenance of the radar level meter, pay attention to checking the following items:

　　1. Regularly check whether the power supply voltage and output current of the instrument are normal.

　　2. Regularly check whether the instrument's antenna is adhered to dirt.

　　3. Check whether the connection between the instrument and the tank is firm.

　　4. Check whether the sealing conditions of the joints of each component are good.

　　5. Perform calibration regularly.

　　In fact, as long as the radar level meter can be correctly selected and installed, it can ensure long-term stable and reliable operation. Therefore, the instrument users should first start from the root causes such as selection and installation, and then take the best interference elimination measures during use to minimize the probability of instrument failure, truly reflect its reliable and high-precision characteristics, better use of radar level meter, and provide accurate basis for production process control.