In certain applications, the current or voltage signal of a pressure transmitter should never exceed and/or drop below a critical value. Played 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 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 may happen deliberately, for instance when cleaning, in addition to accidentally, for instance through load variations or in the event of a fault. In such cases, the sensor signal will also move outside the defined limits, in order 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 a few situations, trouble-free operation of the entire system can’t be ensured anymore. In such cases, a sign limiting of the pressure transmitter is practical, in order that the output signal is maintained within the required range (e.g. 3.8 ? 21 mA).
Note
An example of a pressure transmitter with that your voltage signal and also 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.