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 have a precise 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. Intelligent may happen deliberately, for instance when cleaning, as well as accidentally, for instance through load variations or in case of a fault. In Scared , the sensor signal may also move beyond your defined limits, so 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 as an error, in some situations, trouble-free operation of the complete system can’t be ensured anymore. In these cases, a sign limiting of the pressure transmitter makes sense, so that the output signal is maintained within the mandatory range (e.g. 3.8 ? 21 mA).
Note
A good example of a pressure transmitter with that your voltage signal plus 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.