Level sensors ? the agony of preference?

If one is looking for a level sensor, you can be quickly overwhelmed by the huge selection. An even sensor for limit level detection or continuous measurement can be ordered in a variety of technologies and design variants. But how do I find the right level sensor for my application?
If one wants to decide on a level sensor, the most important selection criterion is 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 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 results in the exclusion of several technologies, if one is looking for the most economical solution. Although Attractive with combined electronics can communicate both an analogue signal and switching signals, a pure level switch is definitely 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 ? 20 mA or 0 ? 10 V, which let the accurate measurement of level and its variation. The sensors can be based on a number of measurement technologies such as for example magnetostriction, reed-chain technology, hydrostatic, ultrasound, radar and more ? the choice of which varies from manufacturer to manufacturer.
Point measurement with optoelectronic level switch
Level switches in a traditional float switch design offer a mechanical switch contact or, in electronic version, generally a PNP or NPN transistor output. In neuro-scientific switches, additionally, there are a range of measurement technologies such as reed contact technology, optoelectronics, conductivity, vibronic and many more.
Each of these technologies has advantages and disadvantages, and also complex, application-specific limiting factors such as for example conductivity, dielectricity, density, contamination, colour, pressure strength, etc. A reliable statement concerning which technology is most suitable or may be used in a specific application environment can only be produced after thorough assessment and frequently also a final test in the plant itself under real application parameters.
Note
WIKA offers you an extremely wide range of level measuring instruments. More info on optoelectronic level switches, hydrostatic level sensors, float switches and further instruments are available on the WIKA website. You can get videos on the functionality of the individual measuring principles on our YouTube channel. Your contact person will undoubtedly be pleased to help you on selecting the most appropriate product solution.

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