In certain applications, the current or voltage signal of a pressure transmitter must not 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 the pressure on a pressure transmitter lies within the nominal pressure range, then you will see 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. Balanced may happen deliberately, for example when cleaning, and also accidentally, for example through load variations or in the event of a fault. In these 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 can occur.
If now, however, the evaluation electronics are set so they recognise a signal outside of the defined limits being an error, in a few 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 that the output signal is maintained within the mandatory range (e.g. 3.8 ? 21 mA).
Note
Supportive of a pressure transmitter with that your voltage signal as well as 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.