| 摘要 |
PROBLEM TO BE SOLVED: To provide a preamplifying device for a noise meter that is robust against mechanical vibrations from the outside, and to provide the noise meter that uses the same. SOLUTION: This preamplifying device for the noise meter is provided with a case 17 screwed in with connector 10, a pin probe 14 electrically connected to a microphone 3 attached to a tip of the case 17, a guard member 12 arranged in the periphery of the pin probe 14 via an insulation ring 13, an insulating member 16 arranged between the guard member 12 and the case 17, and an electric circuit for processing the output signal from the microphone 3, the electric circuit is mounted on a printed circuit board 11 for forming a clearance 20 between patterns, and erected on the connector 10, an elastomer washer 15 is arranged between a flange 12a of the guard member 12 fixed on the a tip part of the printed circuit board 11 and the insulating member 16, and a stepped part 23 formed on the inner circumferential face 17a in the vicinity of the tip of the case 17 is made to abut against a tapered face 22 formed on an outer circumferential face 16a of the insulating member 16. COPYRIGHT: (C)2008,JPO&INPIT
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