In certain applications, the existing or voltage signal of a pressure transmitter should never exceed and/or drop below a crucial value. This is often 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 you will see 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 instance through load variations or in the event of a fault. In such cases, the sensor signal may also move outside the defined limits, so that, for example, a current signal in the range of 3.6 to 25 mA may appear.
If now, however, Lifetime are set so that they recognise a signal outside the defined limits as an error, in a few situations, trouble-free operation of the complete system cannot be ensured anymore. In such 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
An example of a pressure transmitter with that your 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.