In certain applications, the existing or voltage signal of a pressure transmitter should never exceed and/or drop below a critical value. This could be ensured with the aid of so-called signal limiting.
Why is a sign clamping necessary to begin with?
If pressure gauge 10 bar 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 an originally planned pressure range is exceeded or is dropped below. This can happen deliberately, for example when cleaning, in addition to accidentally, for instance through load variations or in case of a fault. In digital pressure gauge , the sensor signal may 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, the evaluation electronics are set so 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 such cases, a signal limiting of the pressure transmitter is practical, so the output signal is maintained within the required range (e.g. 3.8 ? pressure gauge ).
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.