JP2001228046A - Ultrasonic leak detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic leak detector, in which abnormal sounds larger than an ultrasonic sound radiated by leakage is narrowed down, so as to be output to an output part. SOLUTION: The ultrasonic leak detector 1 is provided with ultrasonic microphones 6, 7, 8 which have directivity. The detector 1 is provided with a signal processing circuit 11, which processes electrical signals detected by the microphones 6, 7, 8. The detector 1 is provided with a headphone 14, which outputs the signals processed by the processing circuit 11. The processing circuit 11 is provided with an automatic volume control part 25, which narrows down a signal, when the signal at a set value or more is input and which outputs the signal to the headphone 14. The control part 25 narrows down the signal, when the signal at the set value or more is input, and it outputs the signal to the output part. As a result, the abnormal sound which is larger than the ultrasonic sound radiated by the leak is not output to the headphone 14 as is.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic leak detecting device used for detecting a leak position of various facilities such as a fluid piping system and a closed container which are installed in many plants and factories.

In equipment such as plants and factories, it is very important to periodically detect the presence or absence of leakage in order to obtain the maximum production volume with the minimum energy consumption and maintain the highest production quality. . When equipment leaks,
Since an ultrasonic wave is generated from a leak location, the position of the leak can be detected by detecting the ultrasonic wave with an ultrasonic leak detection device using an ultrasonic microphone having directivity.

[0003]

2. Description of the Related Art A conventional ultrasonic leak detector is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-253377. The ultrasonic leak detection device disclosed here is a portable probe,
An ultrasonic microphone having directivity, a signal processing circuit that processes an electric signal detected by the ultrasonic microphone,
And an output unit for visually outputting the signal processed by the signal processing circuit.

This ultrasonic leak detection device is used by holding the probe with one hand and gradually changing the direction of the probe, that is, gradually changing the direction of the ultrasonic microphone having directivity. When the fluid leaks from the equipment to be measured to the outside, when the pointing direction of the ultrasonic microphone approaches the direction of the leak position, the ultrasonic waves emitted from the leak position are converted into electrical signals by the ultrasonic microphone. The electric signal is detected, amplified and processed by a signal processing circuit, and visually output to an output unit. And
Since the output value of the output unit becomes maximum when the pointing direction of the ultrasonic microphone coincides with the leak position, the leak position can be detected based on the pointing direction of the ultrasonic microphone at this time.

[0005]

In the above-mentioned conventional ultrasonic leak detecting device, an abnormal sound larger than the ultrasonic wave radiated by the leak, for example, due to a sudden air blow or the like is directly output to the output unit. There was a problem that it was dangerous. Therefore, a technical problem of the present invention is to provide an ultrasonic leakage detection device capable of narrowing down abnormal sound louder than ultrasonic waves radiated by leakage and outputting the abnormal sound to an output unit.

[0006]

Means for Solving the Problems The technical means of the present invention taken to solve the above technical problem is to process an ultrasonic microphone having directivity and an electric signal detected by the ultrasonic microphone. A signal processing circuit, and an output unit for audibly outputting the signal processed by the signal processing circuit, wherein the signal processing circuit narrows down the signal when a certain or more signal is input and outputs the signal to the output unit. An ultrasonic leak detection device having an automatic volume control unit for performing the operation.

[0007]

According to the above-mentioned technical means of the present invention, when an auto volume control section receives a signal of a certain level or more, the auto volume control section narrows down the signal and outputs it to an output section. The abnormal sound louder than the ultrasonic wave is not output to the output unit as it is, and the ear can be protected from the abnormal sound.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an external perspective view of an ultrasonic leak detection device of the present invention, and FIG. 2 is a block diagram of an electric circuit of the ultrasonic leak detection device of the present invention. The probe 2 of the ultrasonic leak detection device 1 has a cylindrical front end 3, a center 4 having a substantially square cross section and a tapered front and rear end, and a rear section 5 having a substantially square cross section. Consisting of The outer diameter of the rear part 5 is large enough to be gripped by one hand.

At the tip 3 of the probe 2, ultrasonic microphones 6, 7, 8 having directivity for detecting ultrasonic waves emitted from equipment to be measured, and directional directions of the ultrasonic microphones 6, 7, 8 And a light source 9 such as a laser pointer for emitting a light beam in the same direction. The ultrasonic microphones 6, 7, 8 are located at the vertices of an equilateral triangle, and the light source 9 is located at the center of the ultrasonic microphones 6, 7, 8 (the center of gravity of the equilateral triangle). A camera 10 such as a CMOS camera for displaying an image in the same direction as the directing directions of the ultrasonic microphones 6, 7, 8 is provided in a tapered portion on the distal end side of the central portion 4 of the probe 2.

A signal processing circuit 11 is provided in a central portion 4 and a rear portion 5 of the probe 2. A display unit 12 such as a liquid crystal panel configuration for visually displaying a signal processed by the signal processing circuit 11 and an operation unit 13 having a plurality of push button keys are arranged on one side surface of the outer surface of the central unit 4. Set up. An output terminal 15 for audibly outputting a signal processed by the signal processing circuit 11 to the headphone 14 or the like on the rear portion 5;
And an input / output terminal 17 for connection with the like. The display unit 12 and the headphones 14 form an output unit.

The signal processing circuit 11 comprises an amplifying section 21, a filter section 22, a detecting section 23, a rectifying section 24, an auto volume control section 25, a laser driving section 26, a storage section 27, and a CPU (central processing section) 28. . The ultrasonic microphones 6, 7, and 8 are composed of an amplifying unit 21, a filter unit 2,
2. It is connected to the display unit 12 through the detection unit 23, the rectification unit 24, and the CPU 28. The detection unit 23 and the CPU 28
The auto volume control unit 25 and the output terminal 15 are connected to the headphones 14. Also, the CPU 28
The light source 9 is connected to the light source 9 through the laser driver 26, and is connected to the personal computer 16 through the input / output terminal 17. CPU 28
Is connected to the camera 10 and the operation unit 13.

When detecting the leakage position of the equipment to be measured,
The rear part 5 of the probe 2 is gripped with one hand, and the power switch of the operation unit 13 is pressed with, for example, a thumb to turn it on. When the power switch is turned on, a light beam such as a laser beam is emitted from the light source 9 such as a laser pointer via the laser driving unit 26. Since the spot of the light beam indicates the directional direction of the ultrasonic microphone to the equipment to be measured, the directional directions of the ultrasonic microphones 6, 7, and 8 can be accurately detected.

The direction of the ultrasonic microphones 6, 7, 8 having directivity is gradually changed by gradually changing the direction of the tip 3 of the probe 2 toward the equipment. When the fluid leaks from the equipment to be measured, when the directivity of the ultrasonic microphones 6, 7, 8 approaches the direction of the leak position, the ultrasonic waves radiated from the leak position are transmitted to the ultrasonic microphone 6 , 7, and 8 as an electric signal and sent to the signal processing circuit 11.

The electric signals detected by the ultrasonic microphones 6, 7, 8 are amplified by an amplifier 21, detected by a detector 23 through a filter 22, and rectified by a rectifier 24.
Are processed by the CPU 28 and displayed on the display unit 12. Further, the electric signal detected by the detection unit 23 is narrowed down to a certain level or more by the automatic volume control unit 25 and output to the headphones 14 through the output terminal 15. With this auto volume control unit 25,
It can protect your ears from abnormal sounds caused by sudden air blows.

When the directivity of the ultrasonic microphones 6, 7, 8 coincides with the leak position, the sensitivity becomes maximum. Therefore, the leak position can be accurately detected by the output value of the display unit 12 and the headphone 15 and the spot of the light beam. Then, the leak position can be recorded accurately by projecting the leak position together with the spot of the light beam by the camera 10. The video of the camera 10 is stored in the storage unit 27 and output to the personal computer 16 or the like through the input / output terminal 17.

[0016]

The present invention has the following specific effects. As described above, according to the present invention, it is possible to provide an ultrasonic leak detection device capable of squeezing an abnormal sound louder than an ultrasonic wave radiated by a leak by an automatic volume control unit and outputting the abnormal sound to an output unit.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing an embodiment of an ultrasonic leak detection device according to the present invention.

FIG. 2 is a block diagram showing an electric circuit of the ultrasonic leak detection device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultrasonic leak detection apparatus 2 Probe 6, 7, 8 Ultrasonic microphone 9 Light source 10 Camera 11 Signal processing circuit 11 12 Display unit 13 Operation unit 14 Headphones 16 Personal computer 21 Amplification unit 22 Filter unit 23 Detection unit 24 Rectification unit 25 Auto volume Control unit 26 Laser drive unit 27 Storage unit 28 CPU

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 15, 2000 (2000.2.1
5)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

Claims (1)

[Claims] 1. An ultrasonic microphone having directivity,
A signal processing circuit for processing an electric signal detected by the ultrasonic microphone; and an output unit for audibly outputting the signal processed by the signal processing circuit. An ultrasonic leak detection device having an automatic volume control unit for narrowing down a signal when the signal is output and outputting the signal to an output unit.