In the liquid level measurement industry, radar level gauges have become the first choice for many users. This is because radar level gauges have a wider range of applications and advantages in installation and use compared to other measuring instruments. Of course, any product will have its own shortcomings. In fact, there are still many issues that need improvement in radar level gauges, which are gradually being improved through our technological advancements. So, let's take a look at the common errors that radar level gauges may encounter? This is how technical personnel who have long dealt with radar level gauges introduced it to me.

　　Generally, the errors generated by radar level gauges mainly stem from errors in instrument installation, which can interfere with the echo signal and cause measurement errors. Therefore, experts remind that during installation, the height of the tank and the size of the beam angle must be considered, and sufficient installation space must be left for the radar level gauge.

　　In addition, the following common errors may occur:

　　1. Measurement dead zone: The output of the radar level gauge during measurement is a 4～20mA current. Due to the measured liquid itself and the probe, there are two dead zones in its measurement, namely the upper dead zone and the lower dead zone. The upper dead zone is the minimum measurable distance between the liquid surface and the upper reference point, which is approximately 0.1m～0.5m; the lower dead zone is at the bottom of the probe, and the measurement result does not change with the change of the actual liquid level in the storage tank.

　　2. Errors caused by the measured liquid: When measuring the interface level, the dielectric constant of the upper liquid must be 10 times greater than that of the lower liquid surface. If the dielectric constants of the two interfaces are not significantly different, it will become a wave pattern. During measurement, since the time used for liquid level and interface level is basically the same, the two returned signals will overlap, affecting the measurement result.

　　3. The viscosity of the measured liquid is too high: Liquids with high viscosity may adhere to the probe, affecting signal transmission and causing measurement errors; if the viscosity is even higher, the medium and the probe will stick together, and the probe must be cleaned regularly in this case.

　　4. Errors generated by the radar level gauge itself: Radar level gauges use radar technology, and most errors come from on-site installation.

　　In order to effectively avoid these potential problems, the following matters should be noted when installing radar level gauges:

　　1. When installing radar level gauges, avoid the inlet, inlet curtain, and vortex, because the liquid injection will produce false echoes with much larger amplitudes than the effective echoes reflected by the measured liquid level. At the same time, the irregular liquid level caused by the vortex will scatter the microwave signal, causing attenuation of the effective signal, so they should be avoided;

　　2. For containers with stirrers, the installation position of the radar level gauge should not be near the stirrer, because stirring will produce irregular vortices, which will cause attenuation of the radar signal. At the same time, the blades of the stirrer will also cause false echoes to the microwave signal, especially when the relative dielectric constant of the measured object is small and the liquid level is low, the influence of the stirrer is more serious;

　　3. When the radar level gauge is used to measure the liquid level of corrosive and easily crystallizing substances, in order to prevent the medium from affecting the sensor, the manufacturer generally uses a structure with a polytetrafluoroethylene measuring window and a separable flange. The temperature of these components cannot be too high, and the maximum temperature of polytetrafluoroethylene is 200℃. In order to avoid the influence of high temperature on the radar antenna and to prevent the crystals on the diaphragm from affecting the normal operation of the instrument, a safety distance of at least 100-800mm is required between the flange end face and the highest liquid level.