Infrared ray sensing device.

摘要

A thermally insulating casing (9) accommodates an infrared ray sensing element (2). The casing has a window (6) which conducts infrared rays to the sensing element. The window is covered with heat absorption gas (7). An infrared ray emitting element (1) may be accommodated within the casing (9). The casing may have a second window (3) which passes infrared ray generated by the emitting element. The second window may be covered with the heat absorption gas (7).