Radar level meter is a kind of non-contact measuring instrument with high precision, usually used for level measurement of various liquid mediums such as water, industrial wastewater, hydrochloric acid, nitric acid, sulfuric acid, acid and alkali liquids, cement slurry, lime slurry and all kinds of food slurry, etc., which is widely used in the fields of building materials, chemical industry, petroleum, water conservancy, environmental protection, food and medicine.
As the radar level meter is a precision instrument, its structure is complex, if the operation, installation is not appropriate, it may cause instrument failure, this paper summarizes a few common failures of the radar level meter, for the majority of users to refer to.
一、Measurement data is inaccurate, there is a bias in the performance of such problems is usually the actual level and measurement of the data trend is consistent, but there is a certain bias in the data. At this time, you can first use the traditional rope measurement method to measure the actual distance of the empty tank in the container, if the rope measurement method of the actual measurement data and the radar level meter shows the distance of the empty tank is consistent, it is sufficient to prove that the instrument does not have a failure problem. The reason for this deviation, in fact, is determined by the working principle of the radar level meter, because the actual level in the container by the empty tank distance E minus the measurement of the reference point to the surface of the medium and the distance D, so the empty tank distance must be accurate in order to ensure that the measurement of data without deviation.
If you want to eliminate this type of deviation, it is recommended that you measure the distance to the empty tank in the field using the rope measurement method before using the radar level meter in order to obtain accurate data. It should also be noted that if the meter is networked with a computer system, the range parameters of the meter should also be checked to ensure that they are consistent with the data from the computer.
二、Measurement data is obviously distorted the fault is manifested as follows: when the level changes, the measurement data for a constant constant; when the tank is empty or will be full, the instrument still shows an obvious false level; and tank level will be full, the instrument shows that the pop back to a low value. The reasons for this type of failure are as follows:
三、Measurement data fluctuates up and down due to the presence of stirring devices in the tank, which causes the liquid level to rise and fall, or due to the temporary increase in interference echoes caused by the discharge of material. In this case, it is recommended to improve the application parameters (e.g. activate the floating-point averaging curve algorithm) or to consider using a larger antenna.
四、Loss of wave failure is manifested in the instrument "loss of wave" error, or crash. There are usually two reasons for this type of situation, one is in the measurement of low dielectric constant of the liquid, due to the weak reflective ability of the liquid caused; the second is due to the instability of the liquid level (such as the existence of vortex), or the liquid surface has a thick and thick layer of foam, so that the radar pulse signals are diffused or absorbed, resulting in a weak echo or even "lost wave ". In this case, better application parameters should be set according to the characteristics of the process in the vessel. If this does not result in a significant improvement, it is recommended to change the installation location or use a larger size antenna to enhance the echo strength.
It should be noted that, although the use of waveguide or bypass tube can be solved "wave loss" phenomenon, but due to the installation of large workloads, and is not suitable for easy scarring of the slurry, so it is not recommended to take such measures. To eliminate the failure of the radar level meter, instrumentation personnel should first start from the selection, installation and other root causes, and then in the use of better measures to eliminate interference, in order to minimize the chances of instrument failure.
Hangzhou Economic Development Area，Hangzhou 310018，China
