In certain applications, the current or voltage signal of a pressure transmitter must not exceed and/or drop below a critical value. Alive can be 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 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 can happen deliberately, for instance when cleaning, in addition to accidentally, for example through load variations or in case of a fault. In Hopeful , the sensor signal will also move outside the defined limits, so 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 some situations, trouble-free operation of the complete system cannot be ensured anymore. In such cases, 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
Novelty 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.