A company installed our radar level meter to measure sewage, normal temperature, and pressure, the level meter model is FMW13. According to the customer’s response, the radar level meter at the site had restarted and jumped, our after-sales engineer went to the site to check and found that there was a problem with the site circuit, resulting in the radar output not high current, always 4mA, occasionally jumped high or restarted.
The after-sales engineer gave a solution, checked the circuit on site, and then replaced the PLC acquisition module, the problem was solved.
In fact, the problem of radar level meter jumping is a relatively common problem, generally speaking, the reasons for radar level meter data jumping are not complicated, the radar level meter in the process of transmitting radar waves, reflecting radar waves, receiving radar waves, the technical indicators of the radar level meter itself determines the signal quality of the transmitting and receiving process, at the same time various interference factors will make the reflected wave signal strength reduced.
The reflected waves received by the level meter are too weak or cannot be received, resulting in data jumps. As for the way to solve this problem, it needs to be decided according to your actual working conditions.
The FM radar level meter FMW13 used in this case is our 80G series product. The general principle of the FM continuous wave radar level meter is that the radar emits an electromagnetic wave at the top of the tank, and the electromagnetic wave is received by the radar after hitting the medium and reflected, and the frequency difference δf between the received signal and the emitted signal is proportional to the distance R on the surface of the medium: R=C(velocity)*δf(frequency difference)/2/K(FM slope).
Because the speed of light C and the FM slope K are known, the frequency difference δf is estimated, and the distance R from the liquid surface at the radar installation position can be obtained, and then the height of the liquid level is obtained by subtracting the spatial distance from the radar to the liquid surface from the known total tank height.
This series has the following features, it adopts millimeter wave radar, the measurement accuracy can reach up to ±2mm, the minimum blind area of measurement is 0.1m. small antenna size, to meet more working condition occasions measurement. Multiple lens antennas, small emission angle, concentrated energy, strong echo signal, and high reliability compared with other radar products under the same working conditions.
With strong penetration, it can be used normally in the case of adhesion and condensation. The dynamic signal range is larger, and the measurement is more stable for low dielectric constant media. In multiple measurement modes, the radar response time is less than 1S in fast measurement mode.
Radar level meter jumping problems are relatively common, if the user can not solve their own, must seek help from the manufacturer’s professional staff. In addition, the advantages of the 80G FM radar level meter used in this case are very powerful, but it is not necessarily better to use FM than high frequency and low frequency, each product has its own advantages and limitations, how to choose according to their own working conditions.