JPS56158931A - Pressure transducer - Google Patents

Abstract

PURPOSE:To obtain a pressure transducer which permits sealing in a sealing composition gaseous atmosphere under atmospheric pressure and which does not require any difficult airtight constitution by obtaining reference pressure by means of a gas contg. He of the pressure equivalent to ambient pressure. CONSTITUTION:For example, a pressure sensitive diaphragm 1 is made by forming a recess in the center of the under surface of a semiconductor single crystal (silicon or the like) thereby providing a strain inducing part. This diaphragm is fixed airtightly to a base plate 2 having a hole 2 communicating with said recess. A pressure lead-in tube 4 for the gas to be measured into the recess of the diaphragm 1 is mounted to the base plate 2, and lead pins 6 are provided through the plate 2 airtightly by the aid of hermetic ceals 5 and are connected to the terminal electrodes of the diaphragm 1 in the chamber 7 constituted of a cover 3 and the plate 2. In this way, with the chamber 7 as a reference pressure chamber, the difference thereof from external pressure is measured. It is difficult to maintain the chamber 7 at a high degree of vacuum, but if a gas of >=16 molecular weights contg. 5-30% He gas, for example, a gaseous N2 is sealed to 1 atmospheric pressure at 20 deg.C, the pressure transducer which does not reguire highly airtight sealing or checking of the degree of vacuum is manufactured.