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In the level measurement industry, radar level gauges have become the top choice for most users when selecting instruments. This is because radar level gauges have a wider range of applications compared to other measuring instruments, and they offer advantages in terms of installation and usage. Of course, every product has its own drawbacks. In fact, radar level gauges still have many issues that need to be addressed urgently, and these are being gradually improved as our technical capabilities advance. So, let’s take a look at the various types of errors that commonly occur in radar level gauges. Generally speaking, errors in radar level measurements are mainly caused by installation mistakes. Such errors can interfere with the echo signals, thereby leading to measurement inaccuracies. To this end, experts advise that when installing it, one must take into account the height of the tank as well as the size of the beam angle, and ensure that sufficient installation space is provided for the radar level gauge. In addition, the following common types of errors also occur: 1: Measurement dead zones: Radar level gauges output a current of 4–20mA during measurement. Due to the properties of the medium being measured and the probe itself, there are two dead zones in its measurement, namely an upper dead zone and a lower dead zone. The minimum distance that can be measured between the upper dead zone liquid level and the upper reference point ranges from approximately 0.1 m to 0.5 m ； The dead zone is located at the bottom of the probe; it is the portion for which the measurement values do not change as the actual liquid level in the tank changes. 2: Errors caused by the medium being measured: When measuring the liquid level, it is required that the dielectric constant of the liquid above be 10 times greater than that of the liquid below. If the dielectric constants of the two interfaces differ by not much, a wave pattern will be formed. During measurement, since the time required for measuring the liquid level and the interface level is roughly the same, the two signals that are returned overlap each other, affecting the accuracy of the measurement results. 3: The viscosity of the liquid being measured is too high: The medium has a high degree of viscosity, and such a liquid is likely to adhere to the probe, interfering with the transmission of signals and causing measurement errors. If the viscosity is even higher, the medium may stick to the probe; in such cases, it is necessary to clean the probe regularly. 4: Errors generated by the radar level gauge itself: Radar level gauges utilize radar technology, and most of the errors that occur stem from the installation at the site. 5. Roughness on the inner wall of the waveguide causes abnormal radar echoes. Radar level gauges that use waveguides have high installation requirements, especially with regard to the smoothness of the inner wall of the waveguide. It is recommended that waveguides be made of stainless steel, and the welding method for waveguides should be plug welding. To effectively avoid these potential problems, the following points should be considered when installing a radar level gauge: 1. When installing a radar level gauge, it is necessary to avoid the feed inlet, feed curtain, and vortices, as the medium injected can generate false echoes with amplitudes much greater than those of the effective echoes reflected by the liquid level being measured. At the same time, the irregular liquid levels caused by vortices scatter microwave signals, leading to a reduction in the intensity of the effective signals; therefore, such vortices should be avoided ； 2. For containers equipped with agitators, the radar level gauge should not be installed near the agitator, as the stirring action creates irregular vortices that can cause attenuation of the radar signal. At the same time, the blades of the stirrer also produce false echoes in the microwave signals. This effect is particularly severe when the relative permittivity of the object being measured is low and the liquid level is low ； 3. When radar level gauges are used to measure the level of corrosive or crystalline substances, in order to prevent the medium from affecting the sensor, manufacturers generally employ a design with a polytetrafluoroethylene measurement window and a separated flange structure. The temperature of these components cannot be too high; the temperature limit for polytetrafluoroethylene is 200°C. To avoid the effects of high temperatures on the radar antenna, and to prevent crystals present on the diaphragm from interfering with the proper operation of the instrument, a safety distance of at least 100–800 mm is required between the flange face and the high liquid level. How to solve accuracy issues with radar level gauges: First of all, when using guided-wave radar level gauges, it is essential to pay attention to the measurement range; operating outside this range not only results in inaccurate measurement data but may also cause damage to the radar level gauge. The measurement range should be calculated starting from the bottom of the tank where the light waves reach it; if the storage tank has a special design with a concave bottom, the liquid level will be below the measurement point in such cases, making it impossible to conduct a measurement. Secondly, when measuring a dielectric medium with a low dielectric constant, if its level is below the liquid level reading and the bottom of the tank is visible, to obtain more accurate measurements, the zero point can be adjusted upward to a position above the bottom of the tank. Although the measurement range can reach the tip of the antenna, this is only under ideal conditions; in reality, the effect of adhesion must be taken into account, so it is advisable to keep the measurement value at a distance of at least 100 mm from the antenna tip. Finally, if the medium being measured is in constant motion, to ensure the accuracy of the measurements, it is recommended to fix the waveguide at the bottom of the storage tank and also at an intermediate position. During welding, it is necessary to maintain the smoothness of the inner wall of the waveguide; to prevent irregularities from interfering with the propagation of waves, it is also important to ensure that the welding is done smoothly.