In certain applications, the existing or voltage signal of a pressure transmitter must not exceed and/or drop below a crucial value. This could 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 have 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, and accidentally, for instance through load variations or in case of a fault. In such cases, the sensor signal will also move beyond your defined limits, so that, for example, a current signal in the range of 3.6 to 25 mA may appear.
If now, however, เกจวัดแรงดัน are set so that they recognise a signal outside of the defined limits as an error, in a few situations, trouble-free operation of the entire system cannot be ensured anymore. In ไดอะแฟรม , a sign limiting of the pressure transmitter makes sense, so the output signal is maintained within the mandatory range (e.g. 3.8 ? 21 mA).
Note
An example of a pressure transmitter with which the 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.