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 in the first place?
If the pressure 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 that an originally planned pressure range is exceeded or is dropped below. This can happen deliberately, for example when cleaning, together with accidentally, for example through load variations or in the event of a fault. In such cases, the sensor signal may also move outside the defined limits, so that, for example, an ongoing signal in the range 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 entire system can’t be ensured anymore. In such cases, a signal limiting of the pressure transmitter is practical, so that the output signal is maintained within the mandatory range (e.g. 3.8 ? Have You Heard ).
Note
An example of a pressure transmitter with that your 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.