| 摘要 |
<P>PROBLEM TO BE SOLVED: To make unusual sound measuring operation to be considerably simplified, by using a tool used for actual measurement of unusual sound without special additional devices, pickup sensitivity of a plurality of measuring tools can be set out simply and correctly at short times and because there is no need to perform confirmation of each sensitivity with single sensor body. Ž<P>SOLUTION: In a unusual sound pickup tool, where an amplification circuit includes gain setting function, having a reference tool 1 equipped with function displaying output level of the amplification circuit and a tool 3 equipped with gain setting function in the amplification circuit, after sensors 2 and 4 of each tool are fixed closely to a measured equipment 18 and the amplification circuit output level of unusual sound or ambient noise picked up by the sensor 2 of the reference tool is set up to be 1/n of a saturating level of the amplification circuit, analysis of variance of the fast Fourier transform output is implemented of unusual sound and ambient noise picked up, respectively, by the sensors of the reference tool and the measuring tool and, based on gain setting of the amplification circuit of the measuring tool, difference is set out approximately to be 0. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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