Level sensors ? the agony of preference?

If one is searching for a level sensor, one can be quickly overwhelmed by the large choice. An even sensor for limit level detection or continuous measurement could be ordered in a variety of technologies and design variants. But how do I find the appropriate level sensor for my application?
If one wants to select a level sensor, the main 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 your level sensor should actually be considered a level switch. However, if it is important to 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 results in the exclusion of many technologies, if one wants probably the most economical solution. Although an even 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 form 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 for example 4 ? Cover-up or 0 ? 10 V, which permit the accurate measurement of level and its variation. The sensors could be based on many different measurement technologies such as magnetostriction, reed-chain technology, hydrostatic, ultrasound, radar and more ? the choice which varies from manufacturer to manufacturer.
Point measurement with optoelectronic level switch
Level switches in a normal float switch design offer a mechanical switch contact or, in electronic version, generally a PNP or NPN transistor output. In the field of switches, there are also a range of measurement technologies such as reed contact technology, optoelectronics, conductivity, vibronic and many more.
Each one of these technologies has benefits and drawbacks, and complex, application-specific limiting factors such as conductivity, dielectricity, density, contamination, colour, pressure strength, etc. A trusted statement concerning which technology is the most suitable or may be used in a specific application environment can only just be made after thorough assessment and frequently 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 additional instruments can be found on the WIKA website. You can find videos on the functionality of the individual measuring principles on our YouTube channel. Your contact person will undoubtedly be pleased to advise you on the selection of the most likely product solution.