In certain applications, the current or voltage signal of a pressure transmitter should never exceed and/or drop below a crucial value. This is often ensured using so-called signal limiting.
Why is a sign clamping necessary in the first place?
If Spectacular 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 may happen deliberately, for example when cleaning, together with accidentally, for instance 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 can occur.
If now, however, the evaluation electronics are set so that they recognise a signal outside of the defined limits being an error, in a few situations, trouble-free operation of the entire system cannot be ensured anymore. In these 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
A good example 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.