PROTECTIVE OBSERVATION APERTURE FOR AIR DIFFERENTIAL PRESSURE

Disclosed is a protective observation aperture for air differential pressure that relates to the observation aperture of an industrial television installed on the side wall of a tin bath on the production line of float glass and which is used for monitoring the working conditions of an edge roller and glass forming in the tin bath. The utility model is blocked off by an aperture plate whose air passage diameter is obviously decreased so as to effectively keep the lens of the observation aperture clean and avoid high-temperature explosion, and the lens can be changed or cleaned conveniently thereby. The utility model alleviates workmen's labor intensity and has direct benefit to the quality and the production of glass manufacturing.