6. Reliability and safety

Like most measuring devices, level sensors are used to protect equipment with a very high economic value, and to monitor hazardous installations. Naturally, there is a hierarchy of human and material risks involved. Whatever the appropriateness of the measurement principles used and the quality of manufacture, no instrument can claim absolute reliability. The solution is to operate by redundancy, multiplying the number and/or type for an application where safety is particularly important.

The fact that more and more units are operated with a minimum of personnel, or are even fully automatic, implies greater reliability. As a result, operators appreciate devices capable of self-declaring a malfunction remotely, so-called "fail-safe" devices which, whatever the fault affecting them, react as if they were announcing the logical fault they are responsible for monitoring,...