ANALOG Pirani gauge High Pressure Analog Pirani Gauge Model DHVE 180 Change of pressure in vacuum systems brings about a rise or fall in number of gas molecules present and hence a rise (or) fall in the thermal conductivity of the gas. Thus the heat loss of constant voltage electrically heated filament in the system varies with the pressure. The pirani gauge head filament has high temperature co-efficient of resistance. So a slight change in system pressure brings about useful change in filament resistance resulting in an out of balance of the wheat stone bridge where filament forms one of the arms. This electrically heated filament is an arm of a self balancing wheat stone bridge circuit. An automatic control amplifier corrects bridge voltage automatically, so that the filament temperature is kept constant around 120°C throughout the whole measuring range. Thus the required bridge voltage (which varies depending upon the pressure at the sensor head filament) is a measure of the pressure which after proper conditioning and calibration is displayed on the meter Details Compact solid state electronics Two gauge head capability Factory calibrated Reliable and repeatable pressure indications Excellent Zero stability With setpoint controller