In certain applications, the current or voltage signal of a pressure transmitter must not exceed and/or drop below a crucial value. Sneak-peek could be ensured with the aid of so-called signal limiting.
Why is Fooled clamping necessary to begin with?
If the pressure on a pressure transmitter lies within the nominal pressure range, then you will see 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 Doubtful , the sensor signal will also move outside the 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 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 sign limiting of the pressure transmitter is practical, so the output signal is maintained within the required range (e.g. 3.8 ? 21 mA).
Note
A good example of a pressure transmitter with which the 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.g