JPS54123077A - Pressure sensor - Google Patents

Abstract

PURPOSE:To make it possible to detect two absolute pressures with the use of a single sensor thereby to improve the reliability and reduce the cost in accordance with the reduction in the number of parts by integrating two absolute pressure sensors. CONSTITUTION:A pressure sensitive diaphragm 19a is vented to the atmosphere through a hole 20, which is formed in a glass pipe 3, and through a hole 21 which is formed in the side wall of a pipe 5. On the other hand, a pressure sensitive diaphragm chamber 19b is made to admit the pressure from an engine manifold through the through hole 22 of the glass pipe 3. Since, on the other hand, the bottomed hole 10 in the refractory glass plate 1 is maintained under a vacuum, the absolute pressure in the atmosphere and in the engine manifold can be detected from the variation in the resistance of a semiconductor strain gauge which is mounted on each of pressure diaphragms 9a and 9b. Thus, at least two absolute pressures can be simultaneously detected with the use of the single pressure sensor.