If one is looking for a level sensor, one 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 wants to select 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 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 several technologies, if one is looking for 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 own variation. The sensors could be based on a variety of measurement technologies such as magnetostriction, reed-chain technology, hydrostatic, ultrasound, radar and more ? the choice of 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 neuro-scientific switches, there are also a range of measurement technologies such as reed contact technology, optoelectronics, conductivity, vibronic and many more.
Luxurious of these technologies has advantages and disadvantages, along with complex, application-specific limiting factors such as conductivity, dielectricity, density, contamination, colour, pressure strength, etc. A trusted statement concerning which technology is the most suitable or can be used in a particular application environment can only be made after thorough assessment and often also your final test in the plant itself under real application parameters.
Note
WIKA offers you an extremely wide selection of level measuring instruments. Is Here on optoelectronic level switches, hydrostatic level sensors, float switches and further instruments can be found on the WIKA website. You can get videos on the functionality of the average person measuring principles on our YouTube channel. Your contact person will be pleased to advise you on selecting the most likely product solution.