INTEGRAL MANIFOLD ABSOLUTE PRESSURE AND AMBIENT ABSOLUTE PRESSURE SENSOR

摘要

A combination manifold absolute pressure and ambient absolute pressure sensor utilizing a single absolute pressure sensor and a second sensor which is devised to sense the difference between the manifold pressure and atmospheric pressure. The second sensor is provided with a switch mechanism actuated by a diaphram at a preselected pressure difference between manifold pressure and atmospheric pressure. The actuation of the switch mechanism causes a sample-and-hold circuit to sense the instantaneous manifold absolute pressure at the time of actuation of the switch and electrically add the sensed manifold pressure to the set difference between the manifold pressure and atmospheric pressure to provide a signal indicative of ambient absolute pressure. This signal is utilized to provide altitude compensation in a fuel injection system.