A new miniaturized thin film Pirani type vacuum sensor that detects pressure from 1 X 10(-5) to 760 Torr was developed. The compact instrument is attitude insensitive, rugged, and has rapid response to pressure variations. The very small dimension between the heating element and the heat sink prevents the flow from entering into the viscous regime thus resulting in a predominately conductive heat transfer over the entire pressure range. This removes the complexities introduced into the pressure versus output curve by convective heat transfer. The output is linear from 1 x 10(-4) to 1 Torr, and then monotonically increases beyond 760 Torr. A unique feature of this instrument is the use of a microprocessor to compute the sensor power from the analog voltage and current. In the molecular flow regime, the absolute pressure is directly proportional to the power dissipated by the surrounding gas. By measuring the power, the sensor rejects most of the errors introduced by ambient temperature variations. The analog-to-digital converters for both the current and the voltage signals use the Sigma-Delta conversion method to reject electrical noise by the averaging technique. This results in the stable signal detection of pressure down to 1x10(-5) Torr. The instrument is thermally stable over an ambient temperature range of 0-50 degrees C when the pressure is between 1 X 10(-4) and 760 Torr.