In certain applications, the current or voltage signal of a pressure transmitter must not exceed and/or drop below a crucial value. This could be 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 there will be 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. This may happen deliberately, for example when cleaning, along with accidentally, for instance through load variations or in case of a fault. In these cases, the sensor signal may also move beyond your defined limits, in order that, for example, a current signal in the number of 3.6 to 25 mA can occur.
If now, however, the evaluation electronics are set so that they recognise a signal outside the defined limits as an error, in a few situations, trouble-free operation of the entire system can’t be ensured anymore. In such 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
digital pressure gauge of a pressure transmitter with that your 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.