The PON-100 gauge contains of a fine heated tungsten wire (also known as filament) suspended in a gas which will lose heat to the gas as its molecules collide with the wire and remove heat. If the gas pressure is reduced, the number of molecules present will fall proportionately, and the wire will lose heat more slowly. Measuringthe heat loss is an indirect indication of pressure. The electrical resistance of a wire varies with its temperature, so the resistance indicates the temperature ofwire.
The gauge can communicate with a common PLC through RS485, or with a standard PC through RS485/USB converter. As well as outputs an analog signal as a logarithm of the pressure over the whole measurement range, therefore, a module of ADC can collect the analog voltage then calculate the corresponding pressure.