In certain applications, the existing or voltage signal of a pressure transmitter should never exceed and/or drop below a critical 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 have 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 instance when cleaning, as well as accidentally, for instance through load variations or in the event of a fault. In digital pressure gauge , the sensor signal will also move beyond your defined limits, in order that, for example, an ongoing signal in the range of 3.6 to 25 mA may appear.
If now, however, pressure gauge are set so they recognise a signal outside the defined limits as an error, in some 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 mandatory range (e.g. 3.8 ? 21 mA).
Note
A good example of a pressure transmitter with which the voltage signal and also the current signal could be limited may be the model S-20 (for general industrial applications) or the model MH-3 (for mobile working machines) from WIKA.