Sensor unit and airtightness inspection device

Abstract

A lithium ion battery () that is a test object is housed in a vacuum chamber (). An initial exhaust pipe () and an inspection exhaust pipe () are connected to the upper portion of the vacuum chamber (). The inside of the vacuum chamber () is subjected to an initial exhaust through the initial exhaust pipe () to lower the pressure inside the vacuum chamber () to an inspection pressure (Pe). Thereafter, an inspection exhaust is performed through the inspection exhaust pipe (). A sensor unit () is interposed in the inspection exhaust pipe (). Exhaust gas passing through the inspection exhaust pipe () flows into the sensor unit () from an inlet port, and is caused to flow perpendicularly toward the sensor face of a gas sensor by a nozzle provided inside the sensor unit (). The exhaust gas passes through the inside of the gas sensor, and is discharged to outside of the sensor unit () from an exhaust port.