In certain applications, the current or voltage signal of a pressure transmitter should never exceed and/or drop below a crucial value. This could be ensured with the aid of so-called signal limiting.
Why is a signal 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 may happen deliberately, for example when cleaning, as well as accidentally, for example through load variations or in case of a fault. In these cases, the sensor signal may also move beyond your defined limits, in order that, for example, a current signal in the range 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 some situations, trouble-free operation of the complete system can’t be ensured anymore. In Official , a sign limiting of the pressure transmitter is practical, so that the output signal is maintained within the required range (e.g. 3.8 ? 21 mA).
Note
An example of a pressure transmitter with that your voltage signal and also the current signal could be limited is the model S-20 (for general industrial applications) or the model MH-3 (for mobile working machines) from WIKA.