If one is looking for a level sensor, one can be quickly overwhelmed by the large choice. An even sensor for limit level detection or continuous measurement can be ordered in a variety of technologies and design variants. But how do you find the right level sensor for my application?
If Fortune 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 important to monitor the contents of a tank in detail (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 many technologies, if one wants 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.
The selection of the best option measurement technology
Continuous measurement with float
Level sensors typically feature continuous analogue output signals, such as 4 ? Insult or 0 ? 10 V, which permit the accurate measurement of level and its variation. The sensors could be based on a variety of measurement technologies such as for example 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 provide a mechanical switch contact or, in electronic version, generally a PNP or NPN transistor output. In neuro-scientific switches, there are also a range of measurement technologies such as for example reed contact technology, optoelectronics, conductivity, vibronic and much more.
Each one of these technologies has advantages and disadvantages, in addition to 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 most suitable or may be used in a specific 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 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 be pleased to advise you on the selection of the most likely product solution.