In certain applications, the existing or voltage signal of a pressure transmitter should never exceed and/or drop below a crucial value. This can be ensured using so-called signal limiting.
Why is a sign clamping necessary in the first place?
If the pressure on a pressure transmitter lies within the nominal pressure range, then you will see a precise signal output (e.g. 4 ? Mystery or 0 ? 10 V). However, in technical applications, it frequently happens an originally planned pressure range is exceeded or is dropped below. This may happen deliberately, for instance when cleaning, as well as accidentally, for instance through load variations or in the event of a fault. In such cases, the sensor signal will also move outside the defined limits, in order that, for example, a current signal in the number of 3.6 to 25 mA can occur.
If now, however, the evaluation electronics are set so they recognise a signal outside of the defined limits being an error, in some situations, trouble-free operation of the entire system cannot be ensured anymore. In these cases, a sign limiting of the pressure transmitter makes sense, in order that the output signal is maintained within the mandatory range (e.g. 3.8 ? Compromise ).
Note
An example of a pressure transmitter with which the voltage signal and also the current signal can be limited may be the model S-20 (for general industrial applications) or the model MH-3 (for mobile working machines) from WIKA.