Level sensors ? the agony of preference?

If one is searching for a level sensor, you can be quickly overwhelmed by the huge selection. A level sensor for limit level detection or continuous measurement can be ordered in a number of technologies and design variants. But how do you find the right level sensor for my application?
If one wants to select a level sensor, the most important selection criterion may be the electrical output function. If one really wants to monitor a limit in a tank, e.g. dry running (empty) or overfilled (full), then the level sensor should actually be considered a level switch. However, if it’s vital that you monitor the contents of a tank at length (e.g. 0 ? 100 % fill level), then one needs continuous measurement (= level sensor).
The distinction between level sensor and level switch automatically leads to the exclusion of many technologies, if one wants the most economical solution. Although a level sensor with combined electronics can communicate both an analogue signal and switching signals, a pure level switch is always the cheaper solution, if the application is limit level measurement only.
The selection of the best option measurement technology
Continuous measurement with float
Level sensors typically feature continuous analogue output signals, such as 4 ? digital pressure gauge or 0 ? 10 V, which permit the accurate measurement of level and its variation. The sensors could be based on various measurement technologies such as for example magnetostriction, reed-chain technology, hydrostatic, ultrasound, radar and many more ? the choice of which varies from manufacturer to manufacturer.
Point measurement with optoelectronic level switch
Level switches in a traditional float switch design provide a mechanical switch contact or, in electronic version, generally a PNP or NPN transistor output. In neuro-scientific switches, there are also a number of measurement technologies such as reed contact technology, optoelectronics, conductivity, vibronic and many more.
Each one of these technologies has advantages and disadvantages, in addition to complex, application-specific limiting factors such as for example conductivity, dielectricity, density, contamination, colour, pressure strength, etc. A reliable statement as to which technology is the most suitable or can be used in a specific application environment can only be produced after thorough assessment and often also a final test in the plant itself under real application parameters.
Note
WIKA offers you a very wide selection of level measuring instruments. Further information on optoelectronic level switches, hydrostatic level sensors, float switches and further instruments can be found on the WIKA website. digital pressure gauge could find videos on the functionality of the individual measuring principles on our YouTube channel. Your contact person will undoubtedly be pleased to help you on the selection of the most likely product solution.