There has recently been an increasing need in various automotive monitoring and control systems for a simply structured and highly reliable high-pressure sensor to detect the higher pressures of oils, hydraulic fluids, air and air conditioning refrigerants.
A simple, newly devised approach to sealing oil filled high-pressure sensors is introduced in this paper. The new structure utilizes a resin instead of the metal and glass conventionally used for hermetic sealing oil filled high-pressure sensors. This is made possible by the combined use of oils with large effective molecular diameters and carefully optimized design of shape and size of the sealing faces between sensor parts. The use of a sealed metal diaphragm allows for extensive use of the sensor with many different kinds of pressure media and in various applications. Integration of all of the electronic parts, including the pressure sensing element and the amplifying circuit, onto a single chip contributes further to the expectation of a highly reliable, low cost sensor.