In certain applications, the current or voltage signal of a pressure transmitter should never exceed and/or drop below a critical value. This can be ensured with the aid of 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 there will be 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 may happen deliberately, for instance when cleaning, in addition to 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, the evaluation electronics are set so they recognise a signal outside of the defined limits being an error, in some situations, trouble-free operation of the complete system cannot be ensured anymore. In such cases, a signal limiting of the pressure transmitter makes sense, so the output signal is maintained within the required range (e.g. 3.8 ? เกจวัดแรงดันเบนซิน ).
Note
An example of a pressure transmitter with that your voltage signal plus 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.