JP2594943B2 - Acoustic intensity wattmeter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an acoustic intensity wattmeter used for exploring a sound source, and more particularly, to an acoustic sound suitable for exploring a sound source with high efficiency and high accuracy. It relates to an intensity wattmeter.

[Conventional technology]

In order to take measures against noise of equipment and the like in a short time and economically, high-precision technology for detecting a noise source has become indispensable, and an acoustic intensity wattmeter has attracted attention as a measuring device.

A conventional sound intensity wattmeter is disclosed in
As described in JP-A-256226, a sound wave sensor unit consisting of two sound wave sensor pairs disposed outward on each other at equal distances from the intersection of said axes on two orthogonal linear axes, It comprises a support section for the sensor, a calculation section for calculating the direction and intensity of the sound wave from the output from the sensor, and a display section for calculation results joined to the support section for the sound wave sensor section.

According to this conventional technique, the direction and magnitude of intensity in two orthogonal directions connecting a pair of sound wave sensors are measured, and measurement of a target whose sound source position or its sound volume changes with time is measured. Sometimes, the direction of a sound source is detected in real time and displayed two-dimensionally on an LED or liquid crystal. Furthermore, in this prior art, the sound wave sensor unit is joined to the display unit via the support unit, and the sensor unit and the display unit are integrated, and the measurer sets the direction of the sound wave as a relative direction from the measurer. It can be grasped.

[Problems to be solved by the invention]

When it is necessary to move the measuring point finely, it is necessary to move the display unit having a large volume and weight together with the sound wave sensor unit, that is, it is necessary to move the measurer,
There is a problem that it is difficult to apply the above-described measuring device when there is little room to install the measuring device, or when it is unavoidable that the measurement position is separated from the measurement position, such as measurement under extreme conditions.

This problem can be solved if the sound wave sensor unit and the display unit are separated so that the sound wave sensor unit can be moved independently. However, in the above prior art, since the sound wave sensor and the display unit move integrally, the measurer can easily understand the direction of the displayed sound source and the direction of the actual sound source by associating them. And the display unit, there is a problem in that it is not possible to determine the direction of the sound source displayed on the display unit.

It is an object of the present application to provide an acoustic intensity wattmeter that facilitates movement of a sound wave sensor and allows a user to easily grasp the correspondence between a displayed sound source and an actual sound source.

[Means for solving the problem]

On two orthogonal linear axes, a sound sensor section having two pairs of sound sensors arranged equidistantly outward from each other at the same distance from the intersection of the axes, based on the output of each sensor pair of the sound sensor section. In a sound intensity wattmeter including a calculation unit that calculates the magnitude of the sound wave in each axial direction, and a display unit that displays the direction of the sound source and the size of the sound wave of the sound source based on the calculation result, the sensor unit includes: , The display unit is movable independently of the display unit, the display unit, the X-axis and Y-axis corresponding to the X-axis and Y-axis of the sensor pair is shown on the screen, the said from the arithmetic unit This is achieved by a configuration having an output unit that combines and displays each of the calculation results of the magnitude of the sound wave for each axial direction.

[Action]

Since the two pairs of sound wave sensors are separated from the display unit, they can be moved freely. The display unit shows the x-axis and the y-axis corresponding to the X-axis and the Y-axis of the sound wave sensor. The calculation unit calculates the magnitude of the sound wave according to the output of each sensor pair. The axial direction of the sensor pair and the X axis and Y on the screen
The direction of the sound wave is displayed by aligning each of the axes. Therefore, the measurer can determine the direction of the sound source as the direction on the coordinate plane formed by each axis with the intersection of each axis of the acoustic wave sensor pair as the center.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an external view of a sound intensity wattmeter according to one embodiment of the present invention. The acoustic intensity wattmeter comprises a box section 5 containing a CRT display device 4 and an acoustic wave sensor section 1 connected to the box section 5 via a cable 3 and a support section 2. In addition to the CRT display device 4, a display unit 6 for digitally displaying the magnitude of noise is provided, and further, an arithmetic circuit described later is provided therein. 7 and 8 are C respectively
These are a vertical display position variable knob and a horizontal display position variable knob of the RT display device 4.

FIG. 2 is a detailed configuration diagram of the sound wave sensor unit 1. Small electret condenser microphones 12 and 13 are arranged opposite to each other in the cylindrical distal end of the support portion 2, and the microphones 12 and 13 are separated by a predetermined distance via a spacer 16. The tip of the support 2 is provided in the direction of the tip (hereinafter referred to as X).
(Hereinafter, referred to as Y direction) is fixed, and small electret condenser microphones 14, 15 are opposed to each other in the cylinder. These two microphones 14 and 15 are also separated by a predetermined distance via a spacer 16. Each microphone 12, 13, 14, 15
The acoustic signal converted into an electric signal at step (1) is input to an arithmetic circuit shown in FIG.

The arithmetic unit includes a buffer unit 20 for amplifying the outputs A, B of the sensors 12, 13, 14, and 15 and performing impedance matching, and an arithmetic circuit 21. The arithmetic circuit 21 takes the output A, added value and subtraction value, obtains the integrated value of the subtraction value, calculates the Intenshitei component I _X in the X direction by multiplying the added value and the integrating value, Similarly, the intensity component I _Y in the Y direction is calculated from the output B.

The CRT display device 4 includes a vertical deflection plate 23, a horizontal deflection plate 24, and an amplifier for amplifying the outputs of the intensity components I _Y and _IX and applying the amplified outputs to the respective deflection plates 23 and 24.

Next, the operation of the acoustic intensity wattmeter having the above-described configuration will be described.

When detecting a noise source of a device, an acoustic intensity wattmeter is installed near the device, and the support unit 2 is gripped and the sound wave sensor unit 1 is directed in an appropriate direction. When electric signals corresponding to the input sound intensity are output from the sound wave sensors 12 and 13 to the calculation unit, these signals are input to the calculation circuit 21 via the buffer unit 20 and the intensity component _IX is calculated. Is done. When electric signals corresponding to the input sound intensity are output from the sound wave sensors 14 and 15 to the calculation unit, these signals are input to the calculation circuit 21 via the buffer unit 20 and the intensity component I _Y Is calculated. When these components I _Y and I _X are applied to the vertical deflection plate 23 and the horizontal deflection plate 24 of the CRT display device 4, as shown in FIG. 4, a bright line 17 indicating the direction of the noise source is formed on the fluorescent screen. be painted. FIG. 3 is a principle diagram for explaining that the bright line 17 is directed to the noise source. Now, X
It is assumed that a sound wave enters the sound wave sensor unit 1 at an angle α with respect to the direction. The angle α is given by tan α = | I _Y / I _X | (1) Accordingly, by applying the respective intensity components I _Y and I _X to the vertical and horizontal deflection plates 23 and 24, the sound source direction is indicated by the bright line 17 on the fluorescent screen. The magnitude | I | of the sound intensity I is Is obtained as A circuit that performs such an operation can be configured by two multipliers, an adder, and a square root circuit. The magnitude | I | of the sound intensity I is displayed on the digital display unit 6. The radiation indicated by reference numeral 19 in FIG. 4 is an angle scale.

FIG. 5 is another embodiment of the display method of the fluorescent screen. When the sound source fluctuates with time, the direction and magnitude of the sound source change every moment. However, when represented by a resturge waveform as shown in FIG. 5, for example, the direction of the sound source is represented by bright lines 17, 17 '. The change in size can be visually grasped as a quantitative figure.

As described above, according to the present embodiment, since the direction and size of the sound source, that is, the sound intensity vector can be easily quantitatively and visually observed, the sound source can be searched in a short time and with high accuracy. effective. In this embodiment,
Although the CRT display device is used as the display device, the size of the display device is slightly increased. However, since the sound intensity vector can be displayed by the beam, the display image becomes clear. Further, when the sound intensity vector fluctuates with time, the sound intensity vector can be displayed with a resturge waveform.

In the present embodiment, the two-dimensional sound intensity vector is displayed on the display device using two pairs of sound wave sensors. However, the present invention is not limited to this, and a multi-sensor configuration of three or more pairs is used. Dimensional display can also be performed. For example, if a pair of sensors are mounted in the Z direction perpendicular to both the X and Y directions and three-dimensionally displayed, a more rapid sound source search becomes possible.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, a measurer can move a sound wave sensor easily and it has the effect that a measurer can grasp | ascertain the position direction of a sound source accurately.

[Brief description of the drawings]

FIG. 1 is an external view of an acoustic intensity wattmeter according to one embodiment of the present invention, FIG. 2 is a configuration diagram of a sound wave sensor unit shown in FIG. 1, FIG. 3 is a principle explanatory diagram, FIG. FIG. 5 is a fluorescent screen display diagram, and FIG. 6 is a configuration diagram of a calculation unit. 1 ... Sound wave sensor part, 2 ... Support part, 3 ... Cable,
4. CRT display device, 5. Box box, 6.
... Digital display unit, 12,13,14,15 ... Sound wave sensor (electret condenser microphone), 17 ... Sound intensity vector display bright line.

 ──────────────────────────────────────────────────の Continuation of the front page (72) Inventor Yasunori Narukawa 32nd Miyukicho, Kodaira City Hitachi Electronics Co., Ltd. Koganei Plant (56) References JP-A-61-256226 (JP, A)

Claims (1)

(57) [Claims] 1. A sound wave sensor section having two pairs of sound wave sensors disposed on the two orthogonal linear axes at equal distances from the intersection of the axes and facing outward from each other, and each sensor pair of the sound wave sensor section. A sound intensity wattmeter comprising: a calculation unit for calculating the magnitude of the sound wave in each axial direction based on each output; and a display unit for displaying the direction of the sound source and the size of the sound wave of the sound source based on the calculation result. In the above, the sensor unit is movable independently of the display unit, and the display unit displays an X axis and a Y axis corresponding to the X axis and the Y axis of the sensor pair on a screen, An acoustic intensity wattmeter having output means for synthesizing and displaying each of the calculation results of the magnitude of the sound wave for each axial direction from the calculation unit.