In certain applications, the existing or voltage signal of a pressure transmitter must not exceed and/or drop below a crucial value. This is often ensured using so-called signal limiting.
Why is a sign clamping necessary to begin with?
If the pressure on a pressure transmitter lies within the nominal pressure range, then you will see a precise signal output (e.g. 4 ? 20 mA or 0 ? 10 V). However, in technical applications, it frequently happens that an originally planned pressure range is exceeded or is dropped below. This can happen deliberately, for example when cleaning, and also accidentally, for instance through load variations or in the event of a fault. In these cases, the sensor signal may also move outside the defined limits, so that, for example, a current signal in the range of 3.6 to 25 mA can occur.
If now, however, the evaluation electronics are set so that they recognise a signal outside of the defined limits being an error, in a few situations, trouble-free operation of the entire system cannot be ensured anymore. In such cases, a signal limiting of the pressure transmitter is practical, in order that the output signal is maintained within the required range (e.g. 3.8 ? Tense ).
Note
A good example of a pressure transmitter with which the voltage signal and also the current signal can be limited is the model S-20 (for general industrial applications) or the model MH-3 (for mobile working machines) from WIKA.