Patent ID: 6698273
Filing Date: 2004-03-02
Classification: G01N

Abstract:
An apparatus for inspecting the airtightness of a gas sensor including a gas sensor element, a sub assembly, and an atmosphere-side cover, the gas sensor element having a reference gas chamber and being disposed in the sub assembly, the atmosphere-side cover covering a base end side of the sub assembly and defining an atmosphere chamber extending outward of the sub assembly, the sub assembly having a measurement gas chamber therein, the gas sensor element being exposed in the measurement gas chamber, the atmosphere chamber communicating with the reference gas chamber, the atmosphere chamber and the measurement gas chamber being airtightly isolated from each other, the apparatus operating for inspecting the airtightness of the isolation between the atmosphere chamber and the measurement gas chamber, the apparatus comprising:an atmosphere-side jig located at the base end side of the sub assembly; and a measurement gas-side located at a distal end side of the sub assembly; wherein the measurement gas-side jig includes (1) an air chamber into which the distal end side of the sub assembly extends and which communicates with the measurement gas chamber, (2) a first socket receiving the sub assembly whose distal end side extends into the air chamber, and (3) a high-pressure air source supplying a high-pressure air to the air chamber; and wherein the atmosphere-side jig includes (1) a sealed chamber into which the base end side of the sub assembly extends and which communicates with the atmosphere chamber, (2) a second socket receiving the sub assembly whose base end side extends into the sealed chamber, (3) an airtight sealing portion providing airtight contact between the second socket and the sub assembly, (4) a low-pressure air source supplying the sealed chamber with a pressure lower than a pressure of the high-pressure air supplied to the air chamber, and (5) a sensor portion leading to the sealed chamber.