Four reasons for errors in radar level gauge measurement

Four reasons for errors in radar level gauge measurement

The radar level gauge is a common level gauge measurement tool. Because it encounters various problems during the measurement process, the result of the radar level gauge measurement must have errors, causing the error. There are mainly the following aspects:

1, measuring the dead zone

The radar level gauge outputs 4 to 20 mA in the measurement. Due to the liquid itself and the probe, there are two dead zones in the measurement, namely the upper dead zone and the lower dead zone. The minimum distance that can be measured between the upper dead zone and the upper reference point is about 0.1~0.5m. The lower dead zone is at the bottom of the probe. As the actual liquid level in the tank changes, there is no change in the measurement result.
2, the error caused by the measured liquid

When measuring the boundary, it is required that the dielectric constant of the above liquid must be 10 larger than the following, and if it is not much different, it will become a wave pattern. In another case, when the upper layer liquid level is very low, when the measurement is performed, since the liquid level and the boundary time are basically the same, the two signals that are returned will be stacked together, affecting the measurement result and the measurement result. Waveform diagram.

3. The viscosity of the liquid being measured is too large

The liquid has a very high viscosity, such a liquid is likely to adhere to the probe, affecting the transmission of the signal, causing errors in the measurement. If the viscosity is larger, the probes of the double cable are connected together, so the probe must be periodically Cleaning.

4. The error generated by the radar level gauge itself

The radar level gauge uses guided wave radar technology, which is not affected by environmental conditions such as pressure, temperature and humidity. The cause of the measurement itself is mostly due to the installation on site.