Level sensors ? the agony of preference?

If one is searching for a level sensor, you can be quickly overwhelmed by the huge selection. Maul for limit level detection or continuous measurement could be ordered in a variety of technologies and design variants. But how do you find the appropriate level sensor for my application?
If one wants to select a level sensor, the most crucial 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 a level switch. However, if it’s important to monitor the contents of a tank at length (e.g. 0 ? 100 % fill level), the other needs continuous measurement (= level sensor).
The distinction between level sensor and level switch automatically results in the exclusion of several 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 definitely the cheaper solution, if the application form is limit level measurement only.
How To of the most suitable measurement technology
Continuous measurement with float
Level sensors typically feature continuous analogue output signals, such as 4 ? 20 mA or 0 ? 10 V, which let the accurate measurement of level and its own variation. The sensors could be based on a variety of 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 normal 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 variety of measurement technologies such as for example reed contact technology, optoelectronics, conductivity, vibronic and many more.
Each of these technologies has advantages and disadvantages, and 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 just be made after thorough assessment and often also a final test in the plant itself under real application parameters.
Note
Wreaking offers you an extremely wide range of level measuring instruments. More info on optoelectronic level switches, hydrostatic level sensors, float switches and additional instruments can be found on the WIKA website. You could find videos on the functionality of the individual measuring principles on our YouTube channel. Your contact person will be pleased to advise you on selecting the most likely product solution.

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