JP2008026242A - Preamplifier device for noise meter, and noise meter using the same - Google Patents

Abstract

<P>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. <P>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. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a preamplifier device for a sound level meter that processes an output signal of a microphone and a noise level meter using the same.

  As a conventional preamplifier device for a sound level meter, an apparatus in which components constituting an electric circuit such as an operational amplifier and a resistor and a capacitor are electrically connected by aerial wiring in order to increase impedance between the wirings is known. .

  However, in the conventional preamplifier for a sound level meter, since the components constituting the electric circuit are wired in the air, when mechanical vibration is received from the outside, the component vibrates and generates noise due to the vibration. There was a problem. In particular, the handy type sound level meter has a problem in that vibration due to hand shake is recorded as noise.

  The present invention has been made in view of such problems of the prior art, and an object of the present invention is to provide a preamplifier device for a sound level meter that is resistant to external mechanical vibrations and noise using the same. It is intended to provide a total.

  In order to solve the above problems, the invention according to claim 1 is a case in which a case is fixed to a connector, a pin probe electrically connected to a microphone attached to the tip of the case, and an insulating ring around the pin probe. A preamplifier device for a sound level meter, comprising: a guard member disposed; an insulating member disposed between the guard member and the case; and an electric circuit for processing an output signal of the microphone, wherein the electric circuit is the connector An elastic washer is disposed between the flange of the guard member and the insulating member, which is mounted on a printed circuit board standing upright and fixed to the front end portion of the printed circuit board, and an inner peripheral surface near the front end of the case The step portion formed in this is in contact with the tapered surface formed on the outer peripheral surface of the insulating member.

  According to a second aspect of the present invention, there is provided a noise level meter using the noise level preamplifier device according to the first aspect.

According to the first aspect of the present invention, the electrical circuit is mounted on the printed circuit board standing on the connector, and the guard member fixed to the front end portion of the printed circuit board is formed on the inner peripheral surface near the front end of the case. Since the pressing is performed by bringing the portion into contact with the tapered surface formed on the outer peripheral surface of the insulating member, the printed circuit board is firmly fixed to the connector and hardly affected by external mechanical vibration. Therefore, the generation of noise due to the influence of vibration is reduced.

According to the second aspect of the present invention, external mechanical vibration is not recorded as noise, and the reliability of the sound level meter is improved.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a schematic front view of a sound level meter according to the present invention, FIG. 2 is a front view of a partial cross section of the sound level meter preamplifier device according to the present invention, and FIG. It is a principal part expanded sectional view.

  As shown in FIG. 1, the sound level meter according to the present invention includes a sound level meter main body 1, a preamplifier device 2 attached to the noise level meter main body 1, and a microphone 3 attached to the tip of the preamplifier device 2. The sound level meter main body 1 is provided with an arithmetic processing unit (not shown), a display unit 4 and switches 5.

  As shown in FIGS. 2 and 3, the preamplifier device 2 is fixed to the noise meter main body 1 with a connector 10, a printed board 11 standing on the connector 10, and an adhesive or the like fixed to the tip of the printed board 11. A pipe-shaped guard member 12, a pin probe 14 surrounded by the guard member 12 via an insulating ring 13, an elastic washer 15 that contacts an annular flange 12 a formed on the outer peripheral surface of the guard member 12, The insulating member 16 is in contact with the washer 15 and wound around the guard member 12, and the case 17 is wound around the insulating member 16 and screwed into the connector 10.

  The printed circuit board 11 has a gap (slit) 20 formed between the patterns 19 and a component (an operational amplifier, a resistor, etc.) 21 constituting an electric circuit. The pin probe 14 is movable forward and backward and is biased in the protruding direction, and electrically connects the microphone 3 and an input terminal (not shown) of the printed circuit board 11. For example, PTFE (trademark: Teflon) is used for the insulating ring 13, and silicon as an elastic body is used for the washer 15, for example.

  The insulating member 16 has a substantially cylindrical shape, and a tapered surface 22 is formed on the outer peripheral surface 16a. For the insulating member 16, for example, polyacetal copolymer (trademark: Duracon) is used. The case 17 has a substantially cylindrical shape, and a step portion 23 is formed on the inner peripheral surface 17a near the tip, and a female screw (not shown) that meshes with the step portion 24 and the male screw 25 of the connector 10 on the inner peripheral surface 17b near the base end. Engraved. Reference numeral 26 denotes a knurl for fixing the preamplifier device 2 to the sound level meter main body 1.

  The operation of the preamplifier for a sound level meter and the sound level meter using the same according to the present invention configured as described above will be described. When the case 17 is screwed into the connector 10, the stepped portion 23 formed on the inner peripheral surface 17 a near the tip of the case 17 abuts on the tapered surface 22 formed on the outer peripheral surface 16 a of the insulating member 16. Further, the insulating member 16 presses the guard member 12 in the advancing direction of the case 17 through the elastic washer 15.

  Then, the printed circuit board 11 is firmly clamped and fixed by the case 17 and the connector 10 via the insulating member 16, the washer 15, and the guard member 12. Since the step portion 23 and the tapered surface 22 are in contact with each other by a line rather than a surface, rattling between the insulating member 16 and the case 17 is unlikely to occur. Moreover, since the space | gap (slit) 20 is formed between the patterns 19 of the printed circuit board 11, the impedance between the patterns 19 can be raised. The step 24 formed on the inner peripheral surface 17b near the base end of the case 17 serves as a stopper.

  Therefore, even if mechanical vibration is applied to the preamplifier device 2, the vibration does not affect components (such as operational amplifiers and resistors) constituting the electric circuit mounted on the printed circuit board 11 and affects noise measurement. Does not generate noise. Further, the sound level meter using the preamplifier device 2 does not record external mechanical vibration as noise.

  According to the present invention, since a preamplifier device for a sound level meter that is resistant to mechanical vibration can be provided, the reliability and usability of a sound level meter using the same can be improved, and in particular, the demand for handy type sound level meters can be increased.

Outline front view of the sound level meter according to the present invention The front view of the partial cross section of the preamplifier device for a sound level meter according to the present invention The principal part expanded sectional view of the preamplifier apparatus for noise meters which concerns on this invention

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Noise meter main body, 2 ... Preamplifier device, 3 ... Microphone, 10 ... Connector, 11 ... Printed circuit board, 12 ... Guard member, 12a ... Flange, 13 ... Insulation ring, 14 ... Pin probe, 15 ... Washer, 16 ... Insulation Member, 16a ... outer peripheral surface, 17 ... case, 17a ... inner peripheral surface, 20 ... gap, 22 ... tapered surface, 23 ... stepped portion.

Claims (2)

A case fixed to the connector, a pin probe electrically connected to a microphone attached to the tip of the case, a guard member disposed around the pin probe via an insulating ring, the guard member and the case A sound level meter preamplifier device comprising an insulating member disposed between and an electric circuit for processing an output signal of the microphone, wherein the electric circuit is mounted on a printed circuit board standing on the connector. An elastic washer is disposed between the flange of the guard member fixed to the tip and the insulating member, and a step formed on the inner peripheral surface near the tip of the case is formed on the outer peripheral surface of the insulating member. A preamplifier device for a sound level meter which is in contact with a tapered surface. A noise meter using the preamplifier device for a noise meter according to claim 1.