In certain applications, the existing or voltage signal of a pressure transmitter must not exceed and/or drop below a crucial value. This could be ensured with the aid of so-called signal limiting.
Why is a signal clamping necessary to begin with?
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. Lonely may happen deliberately, for example when cleaning, and also accidentally, for instance through load variations or in the event of a fault. In these cases, the sensor signal will also move outside the 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 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
An example 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.