LARGE SOUND PRESSURE PROVISION DEVICE FOR MEASURING AND CALIBRATING MICROPHONE CHARACTERISTIC

摘要

PURPOSE: To realize the small sized and simple sound pressure provision device for measuring and calibrating the microphone characteristic not requiring installation such as an anechoic chamber. ;CONSTITUTION: A large sound pressure provision device is provided with a pressure chamber varying means consisting of a casing in which two cup shaped main bodies 1,2 are screwed directly indirectly to partition a pressure chamber 3 freely adjusting the volume, of a piston 11 reciprocating with a cylinder hole 10 opened toward the pressure chamber and the operation of a cam 7, and with a microphone mount part 12 in which a measured microphone is mounted to the casing in a way of facing the pressure chamber with air-tightness member 15. Since the volume V of the pressure chamber is increased in a range of ΔV=2AS with the reciprocation at a prescribed stroke of a piston caused by the periodic operation of the cam, the inner pressure in the pressure chamber is increased/decreased in a range of Δ=K×(ΔV/V) periodically, resulting that a sound pressure ΔP adjusted optionally is exerted to the microphone.;COPYRIGHT: (C)1993,JPO&Japio