In certain applications, the current 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 Exploit on a pressure transmitter lies within the nominal pressure range, then you will have a defined signal output (e.g. 4 ? 20 mA or 0 ? 10 V). However, in technical applications, it frequently happens an originally planned pressure range is exceeded or is dropped below. This can happen deliberately, for instance when cleaning, along with accidentally, for example through load variations or in case of a fault. In such cases, the sensor signal will also move beyond your defined limits, in order 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 some situations, trouble-free operation of the entire system can’t be ensured anymore. In such 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 that your 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.