If one is looking for a level sensor, you 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 you find the appropriate level sensor for my application?
If one really wants to decide on a level sensor, the most important selection criterion may be the electrical output function. If one 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), 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 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 permit the accurate measurement of level and its own variation. The sensors could be based on a variety of measurement technologies such as magnetostriction, reed-chain technology, hydrostatic, ultrasound, radar and much more ? the choice 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 Rowdy of switches, additionally, there are a variety of measurement technologies such as reed contact technology, optoelectronics, conductivity, vibronic and more.
Each of these technologies has advantages and disadvantages, in addition to complex, application-specific limiting factors such as conductivity, dielectricity, density, contamination, colour, pressure strength, etc. A trusted statement concerning which technology is most suitable or can be utilized in a particular application environment can only be made after thorough assessment and frequently also your final test in the plant itself under real application parameters.
Note
WIKA offers you a very wide selection of level measuring instruments. Adequate 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 the selection of the most appropriate product solution.