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 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 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, together with accidentally, for instance through load variations or in the event of a fault. In these cases, the sensor signal may also move beyond your defined limits, in order that, for example, an ongoing signal in the number of 3.6 to 25 mA may appear.
If now, however, Blood are set so they recognise a signal outside the defined limits being an error, in some situations, trouble-free operation of the entire 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
An example of a pressure transmitter with which the 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.