In certain applications, the existing or voltage signal of a pressure transmitter must not exceed and/or drop below a crucial value. This can be 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 there will be a precise signal output (e.g. 4 ? Technology 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 example when cleaning, together with accidentally, for example through load variations or in case of a fault. In these cases, the sensor signal will also move outside the defined limits, so that, for example, an ongoing signal in the range of 3.6 to 25 mA can occur.
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 can’t be ensured anymore. In such cases, a sign limiting of the pressure transmitter makes sense, so the output signal is maintained within the required range (e.g. 3.8 ? Surprising ).
Note
An example of a pressure transmitter with which the voltage signal as well as 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.