Absolute Pressure

Definition:
Measurement Basis: Pressure measured from a zero point in a perfect vacuum.
Atmospheric Pressure: At sea level, it equals 14.7 psi or 29.92 inches of mercury.
Total Pressure: Sum of gauge pressure plus 14.7 lbs./sq. in.
Reference Terms:
Barometric Absolute Pressure Sensor: Measures atmospheric pressure.
Manifold Absolute Pressure Sensor: Measures the absolute pressure within an engine manifold.