If one is looking for a level sensor, you can be quickly overwhelmed by the large choice. A level sensor for limit level detection or continuous measurement can be ordered in a number of technologies and design variants. But how do I find the right 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 considered a level switch. However, if it is vital that you 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 leads to 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.
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 can be based on many different measurement technologies such as magnetostriction, reed-chain technology, hydrostatic, ultrasound, radar and more ? Scam 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 range of measurement technologies such as for example reed contact technology, optoelectronics, conductivity, vibronic and many more.
Each one of these technologies has advantages and disadvantages, along with 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 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 an extremely wide selection of level measuring instruments. Unseen 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. Best-selling will undoubtedly be pleased to advise you on selecting the most likely product solution.