In certain applications, the current or voltage signal of a pressure transmitter must not exceed and/or drop below a crucial value. Passionate is often ensured using so-called signal limiting.
Why is a signal 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 Assured , it frequently happens that an originally planned pressure range is exceeded or is dropped below. This can happen deliberately, for example when cleaning, and accidentally, for example through load variations or in the event of a fault. In such cases, 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 can occur.
If now, however, the evaluation electronics are set so that they recognise a signal outside the defined limits being an error, in a few situations, trouble-free operation of the complete system can’t be ensured anymore. In these 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 ? 21 mA).
Note
A good example 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.