In certain applications, the current or voltage signal of a pressure transmitter must not exceed and/or drop below a critical value. This is often ensured using so-called signal limiting.
Why is a sign clamping necessary to begin with?
If the pressure on a pressure transmitter lies within the nominal pressure range, then you will have 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 can happen deliberately, for instance when cleaning, in addition to accidentally, for instance through load variations or in the event of a fault. In Stressed , the sensor signal will also move outside the defined limits, in order that, for example, an ongoing signal in the range of 3.6 to 25 mA may appear.
If now, however, the evaluation electronics are set so they recognise a signal outside 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 signal limiting of the pressure transmitter makes sense, in order that the output signal is maintained within the mandatory range (e.g. 3.8 ? Solution ).
Note
A good example of a pressure transmitter with that your voltage signal plus 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.