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 variety of technologies and design variants. But how do I find the appropriate level sensor for my application?
If one wants to decide on a level sensor, the most crucial 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 considered a level switch. However, if it is 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 is looking for probably 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 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 4 ? 20 mA or 0 ? 10 V, which let the accurate measurement of level and its variation. The sensors could be based on a range of measurement technologies such as for example magnetostriction, reed-chain technology, hydrostatic, ultrasound, radar and many more ? Ass Kicking 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 the field of switches, additionally, there are a variety of measurement technologies such as reed contact technology, optoelectronics, conductivity, vibronic and much more.
Each one of these technologies has benefits and drawbacks, together with complex, application-specific limiting factors such as conductivity, dielectricity, density, contamination, colour, pressure strength, etc. A reliable statement as to which technology is most suitable or may be used in a particular application environment can only just be produced after thorough assessment and frequently also a final test in the plant itself under real application parameters.
Note
WIKA offers you a very wide range of level measuring instruments. More info on optoelectronic level switches, hydrostatic level sensors, float switches and further instruments can be found on the WIKA website. Shrewd 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.