Acoustic binary gas sensor for determining water vapor content in hot and polluted exhaust air from industrial drying plants during manufacturing of paperboard, has acoustic cavity resonator, whose wall has two small openings

摘要

The acoustic binary gas sensor has an acoustic cavity resonator (1), an electric or acoustic transducer (2), an acoustic or electric converter (3) and an electronic amplifier (4). The wall of the cavity resonator has two small openings (5,6), whose cross sectional areas are smaller than the wall surface of the cavity resonator. An elongated acoustic resonator (7) is connected with the open end through the former opening of the cavity resonator.