In certain applications, the existing or voltage signal of a pressure transmitter should never exceed and/or drop below a critical value. This is often ensured with the aid of 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 have a defined signal output (e.g. 4 ? Mired 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, along with accidentally, for example 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, a current signal in the number of 3.6 to 25 mA may appear.
If now, however, the evaluation electronics are set so that 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 Ultimate , a sign limiting of the pressure transmitter is practical, so 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 that your 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.