Piston phone has built-in pressure transducer and is for calibration of microphones, comprising a chamber in which microphone can be installed so that a mainly closed chamber can be formed

摘要

#CMT# #/CMT# The piston phone has a built-in pressure transducer and is for calibration of microphones, comprising a chamber (3) in which a microphone (2) can be installed so that a mainly closed chamber can be formed and one or more pistons (5) can be made to move by a motor (8), so that the volume of the closed chamber is altered to match the movement of the pistons, so that the dynamic pressure in the volume is altered, activating the membrane (4) of the microphone. #CMT# : #/CMT# The equipment forms a combined unit containing a barometer or pressure transducer (11) for measurement of static air pressure. #CMT#USE : #/CMT# For calibration of microphones. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The figure displays schematically a layout of the equipment. Non-English words are translated in pencil. 2 : microphone 3 : chamber 4 : membrane of microphone 5 : pistons 8 : motor 11 : barometer or pressure transducer measuring static air pressure.