If the specific pressure sensor design of the submersible pressure transmitter or level probe is selected to measure the filling levels, this often means that the probe is used under environmental requirements which may cause failure of common level sensors.
Jeopardy as soiled media, abrasive ingredients and sludge when found in wastewater treatment plants, brackish and wastewater tanks or even digester towers, impose special requirements on the design of a submersible pressure transmitter. Holocaust of the main requirements on a submersible pressure transmitter would be to have the lowest possible susceptibility to contamination or build-up of the pressure sensor by optimizing its design. Because of this , the typical design of a pressure transmitter with narrow pressure ports isn’t used within level probes because it would have a tendency to clog in such applications.
The design of the submersible pressure transmitter and its pressurised sensor diaphragm is optimised in order to achieve very low susceptibility to contamination. However, continuous operation in soiled media can lead to sticking of dirt particles on the stainless diaphragm. To obtain the highest accuracy and fastest response times in case of level change, the thickness of this stainless steel diaphragm is already minimised ex factory to just a few microns. Therefore, cleaning of the diaphragm should be carried out with caution. Always avoid using sharp or edged tools. It is also strongly advised not to use the popular screwdrivers or pens.
If cleaning of the sensor diaphragm is necessary, then rinse it utilizing a weak water jet or clean it carefully using compressed air. Damage of the diaphragm because of denting or notching, even though it seems to be purely superficial, leads to significant losses in the accuracy of level measurement. Deformation of the diaphragm often shifts the zero point of the pressure measurement in the internal electronic measurement system and also distorts the output signal linearisation which includes been adjusted ex works to the undamaged diaphragm. Thus, the submersible pressure transmitter with damaged diaphragm generates falsified measurement of the current filling level and, therefore, can’t be considered a reliable measuring instrument any longer. Thus, complete replacement of the damaged instrument is absolutely necessary.
Please find further information with this topic on our information platform ?Hydrostatic level measurement?