In certain applications, the current or voltage signal of a pressure transmitter should never exceed and/or drop below a crucial value. This could be ensured with the aid of 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 there will be 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. Exclusivity may happen deliberately, for instance when cleaning, and accidentally, for instance through load variations or in case of a fault. In these cases, the sensor signal may also move beyond your defined limits, so 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 the defined limits being an error, in some situations, trouble-free operation of the complete system can’t be ensured anymore. In such cases, a signal limiting of the pressure transmitter is practical, 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 that your voltage signal as well as 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.