Ultrasonic level gauge
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Our company has purchased ultrasonic level gauges, and although the actual liquid level in the tank remains constant, the level indicated by the computer keeps fluctuating. It is at its lowest at 8 a.m. and at its highest at 4 p.m. Could anyone please help explain this phenomenon?
In general, this situation is not caused by a problem with the sensor, but rather by echo interference. Things such as protrusions on the tank walls or an improper installation location of the level gauge can both cause echo interference. Generally, this interference is eliminated after installing a waveguide. If there is no waveguide, the instrument’s settings usually include an option for suppressing echo interference; following the operation manual should help eliminate this interference. Additionally, incorrect settings within the instrument could also cause this issue for you. Check the settings to see if they match the environment in which the gauge is located, and whether the range is correct.
It might be caused by the movement of the liquid; no spots appeared at 8 a.m. since no liquid had been injected yet. The movement of the liquid was greatest at 4 p.m. Additionally, the speed at which the liquid moves also affects the measurement results.
The answer on the 2nd floor was very insightful; we have encountered similar problems as well!
Regular fluctuations~~ are usually caused by interference·~ Give it a try and see~
Right rotation is caused by echoes; sometimes, volatile gases in the medium can also cause interference.
I think it might be caused by temperature changes. In a closed tank, when there is no inflow or outflow of material, changes in the temperature of the gas phase medium can cause changes in the speed of ultrasound waves (0. 17%/C), and this is why the liquid level appears low in the morning (low temperature results in a lower wave speed, which increases the measurement distance in the gas phase and leads to an underestimated liquid level); it appears high in the afternoon (high temperature results in a higher wave speed, which reduces the measurement distance in the gas phase and leads to an overestimated liquid level). Temperature compensation can be implemented in the software; if no such compensation is available, it’s better to use a radar, as it isn’t affected by temperature. One issue is that if the probe has a thermometer, measurements taken in an open tank will also be inaccurate, as the temperature of the probe will not match that of the gas phase, and errors will always exist. I don’t think it’s caused by interference, as the interference inside the tank is usually constant and does not lead to sinusoidal fluctuations. Since there is no change in liquid level, an inappropriate installation location also does not cause sinusoidal fluctuations.
Can ultrasonic waves be used with waveguides? ? ? I’m hearing about it for the first time
Check whether the medium being measured vaporizes due to rising temperature and condenses on the probe, causing measurement errors; wipe it dry with a dry cloth before observing again. Since ultrasonic waves are highly sensitive to moisture or other condensates on the probe, this issue can generally be resolved by using a wave guide cover with openings on both sides and by wiping it regularly