In certain applications, the existing or voltage signal of a pressure transmitter must not exceed and/or drop below a crucial value. This could 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 defined 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, along with accidentally, for example through load variations or in the event of a fault. In such cases, the sensor signal will also move beyond your defined limits, so that, for example, an ongoing signal in the number of 3.6 to 25 mA may appear.
If now, however, Delight are set so they recognise a signal outside of the defined limits as an error, in a few situations, trouble-free operation of the entire system can’t be ensured anymore. In Clear , 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
A good example of a pressure transmitter with which the voltage signal plus the current signal can be limited is the model S-20 (for general industrial applications) or the model MH-3 (for mobile working machines) from WIKA.