Functional PrincipleThe WPI200 gauge contains of a fine heated tungsten wire (also called a 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. Measuring the heat loss is an indirect indication of pressure. The electrical resistance of a wire varies with its temperature, so the resistance indicates the temperature of wire.
The gauge can display the vacuum pressure by a 5-digit LED or communicate with a standard PC through RS485 or Wireless, as well it outputs an analog signal as a logarithm of the pressure over the whole measurement range, and it has two build-in setpoint switches.