In certain applications, the current or voltage signal of a pressure transmitter must not exceed and/or drop below a critical value. Helpful could be ensured with the aid of so-called signal limiting.
Why is a signal clamping necessary in the first place?
If the pressure on a pressure transmitter lies within the nominal pressure range, then you will see a precise signal output (e.g. 4 ? Tested 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, and accidentally, for example through load variations or in case of a fault. In such cases, the sensor signal may also move beyond your defined limits, so 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 cannot be ensured anymore. In these cases, a sign limiting of the pressure transmitter makes sense, so the output signal is maintained within the required range (e.g. 3.8 ? 21 mA).
Note
Backbone of a pressure transmitter with which the voltage signal and also the current signal could be limited may be the model S-20 (for general industrial applications) or the model MH-3 (for mobile working machines) from WIKA.g