In certain applications, the current or voltage signal of a pressure transmitter should never exceed and/or drop below a critical value. This could be ensured using so-called signal limiting.
Why is a signal clamping necessary to begin with?
If Offensive on a pressure transmitter lies within the nominal pressure range, then there will be a defined 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, in addition to accidentally, for instance through load variations or in the event of a fault. In these cases, the sensor signal will also move beyond your defined limits, in order that, for example, a current signal in the number of 3.6 to 25 mA may appear.
If now, however, the evaluation electronics are set so they recognise a signal outside of the defined limits as an error, in some situations, trouble-free operation of the complete system cannot be ensured anymore. In these cases, a sign limiting of the pressure transmitter makes sense, so 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 plus the current signal could be limited is the model S-20 (for general industrial applications) or the model MH-3 (for mobile working machines) from WIKA.