Consultation regarding ultrasonic level gauges
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The company has a storage tank for which it wants to install an ultrasonic level gauge. Cylindrical vertical stainless steel storage tank with conical top and bottom heads. The cylindrical section is 7500 mm in height and 2800 mm in diameter; the level gauge is intended to be installed on it at a distance of about 500 mm from the center. The medium is generally referred to as a polyether (it belongs to a large category); its density is similar to that of water, and the finished products are often changed, resulting in slight differences in density. It is sealed with nitrogen inside, and the pressure varies between 0 and 10 kPa, being unstable. The temperature is also around room temperature and unstable. Can an ultrasonic level gauge be used in this type of operating condition? If it is to be installed, what potential problems could arise? The accuracy is less than 1 cm.
Polyethers have low volatility, there is a slight positive pressure of nitrogen in the tank, and using ultrasound poses no technical issues. The downside is that ultrasonic level gauges are not very stable; low-quality ultrasonic sensors can cause the level reading to fluctuate. Additionally, their accuracy is generally low. For a tank of 7500 mm in size, an accuracy of 10 mm corresponds to 0.13%, and such accuracy cannot be achieved by ordinary ultrasonic level gauges (for example, the FMU series from E+H has an accuracy of 0.2%). I am not aware of the conductivity of polyethers; if suitable, radar or guided-wave radar would offer much better precision. Based on practical experience, radar also has better stability compared to ultrasonic waves. An immersion-type hydrostatic level gauge combined with a pressure transmitter is also an option.
I agree with what was said on the 2nd floor: it is possible to use ultrasound for this application, but in terms of long-term stability, the problems mentioned there will arise. It is recommended to use radar or guided waves; however, submerged static pressure sensors are not advisable, as there is a nitrogen seal on the tank and the client requires high precision, which could affect the accuracy of the measurement results