In certain applications, the existing or voltage signal of a pressure transmitter must not exceed and/or drop below a critical value. This could 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 precise 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. This may happen deliberately, for example when cleaning, and also accidentally, for instance through load variations or in case of a fault. In Guilt-free , the sensor signal will also move outside the defined limits, so that, for example, a current signal in the range of 3.6 to 25 mA may appear.
If now, however, the evaluation electronics are set so that they recognise a signal outside 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 signal limiting of the pressure transmitter is practical, so 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 as well as 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.