If the precise 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 would cause failure of common level sensors.
Intel as for example soiled media, abrasive ingredients and sludge when used in wastewater treatment plants, brackish and wastewater tanks as well as digester towers, impose special requirements on the design of a submersible pressure transmitter. One 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. For this reason the normal design of a pressure transmitter with narrow pressure ports isn’t used within level probes because it would tend to clog such applications.
The design of the submersible pressure transmitter and its pressurised sensor diaphragm is optimised to experience suprisingly low susceptibility to contamination. However, continuous operation in soiled media can lead to sticking of dirt particles on the stainless steel diaphragm. To get 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 never to use the commonly used screwdrivers or pens.
If cleaning of the sensor diaphragm is essential, then rinse it utilizing a weak water jet or clean it carefully using compressed air. Damage of the diaphragm due to denting or notching, even if it appears to be purely superficial, results in significant losses in the accuracy of level measurement. Deformation of the diaphragm often shifts the zero point of the pressure measurement in the inner electronic measurement system and also distorts the output signal linearisation which has been adjusted ex works to the undamaged diaphragm. Thus, the submersible pressure transmitter with damaged diaphragm generates falsified measurement of the existing filling level and, therefore, can’t be considered a trusted measuring instrument any longer. Thus, complete replacement of the damaged instrument is absolutely necessary.
Please find Belong with this topic on our information platform ?Hydrostatic level measurement?