In certain applications, the existing 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 sign clamping necessary in the first place?
If the pressure on a pressure transmitter lies within the nominal pressure range, then you will see a precise 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 instance when cleaning, together with accidentally, for instance 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 can occur.
If now, however, เพรสเชอร์เกจ are set so they recognise a signal outside of the defined limits being an error, in some situations, trouble-free operation of the entire system cannot 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 ? 21 mA).
Note
A good example of a pressure transmitter with that your voltage signal as well as 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.