JP3150446U - Abnormal noise measurement tool - Google Patents

Abstract

An abnormal noise measurement tool capable of highly sensitive measurement by correcting a sensitivity difference easily and accurately in a short time. An A / D conversion circuit which is configured integrally or separately with an allophone measurement tool and which sets a gain for a reference signal source that emits sound or vibration having a predetermined frequency and magnitude, and an output signal of a sensor unit. And a display function for displaying the input level of the A / D conversion, and the gain of the amplifier circuit so that the sensor unit inputs a signal obtained from the reference signal source to the A / D conversion circuit at a predetermined level. By setting, it is an allophone measurement tool that enables highly accurate measurement by correcting the sensitivity difference of the sensor unit in a short time, easily and accurately. [Selection] Figure 1

Description

Each sensor unit does not have an individual sensitivity correction means, but a reference signal source that emits a sound or vibration having a predetermined frequency and magnitude, and an amplification signal that is input to an A / D conversion circuit by setting the gain of the output signal of the sensor unit The display function that displays the circuit and the input level of A / D conversion is provided, and the signal picked up from the reference signal source by the sensor unit attached to the noise measurement tool is adjusted at a predetermined level by adjusting the gain of the amplifier circuit. An allophone measurement tool that enables high-accuracy measurement by correcting sensitivity differences for any sensor unit in a short time, simply and accurately, by making settings for A / D conversion.

Various noise detection during operation has been put to practical use as one of the judgments as to whether the operation of electrical equipment is normal. In electrical equipment, many abnormal noises such as abnormal noise generated from hard disks, compact disks, fans, solenoids, power supplies, etc., or abnormal noise caused by rubbing caused by magnetic tape, paper running, etc. occur. In addition to being uncomfortable, there are many cases where some kind of malfunction has occurred in the equipment. Whether or not the abnormal noise is in the normal range is often judged by a skilled worker by directly hearing it, but in recent years it has been picked up using a sensor unit such as an acceleration sensor or microphone. Various methods have been put to practical use, such as A / D conversion and Fast Fourier Transform analysis and processing, but in many production processes, abnormal noise is often measured using multiple sensor units. It is necessary to correct the sensitivity variation of the sensor unit. Generally, a sensor and a sensitivity correction amplifier circuit are configured as a unit, and the sensitivity difference of the sensor unit is corrected by gain adjustment before shipment. However, in this configuration, the sensor and the sensitivity correction amplifier circuit are configured as a pair and cannot be separated, resulting in a high cost and large size, and even if a sensitivity difference occurs, there is no sound source as a reference for confirmation and setting. , It is difficult to reset easily and accurately in a short time.

Problems that the device tries to solve

In the noise measurement tool, a sensor unit is configured by incorporating a sensor such as a microphone or an acceleration sensor into the sound collection piece, but measurement errors are likely to occur due to sensitivity differences due to the sensor itself or the way it is incorporated into the sound collection piece. Also, in production processes and the like, there are many cases where abnormal noise is measured and compared using a plurality of sensor units, and individual sensitivity differences of the sensor units used are the largest cause of measurement error. For this reason, it is the biggest challenge to be able to check and correct the sensitivity difference easily and accurately in any sensor unit in a short time.

Means for solving the problem

Amplification that is configured to be integrated with or separate from the noise measurement tool, and that sets the gain of the output signal of the reference signal source and sensor unit that emits sound or vibration having a predetermined frequency and magnitude, and inputs it to the A / D conversion circuit A circuit and a display function for displaying the input level of A / D conversion are provided, and the gain of the amplifier circuit is set so that the sensor unit inputs a signal obtained from the reference signal source to the A / D conversion circuit at a predetermined level. This is a noise measurement tool that enables accurate measurement by correcting the sensitivity difference of the sensor unit in a short time, easily and accurately.

Effect of device

The sensor unit is not equipped with individual sensitivity correction means, and is composed of a sound collection piece and a sensor, so that it is realized in a very small size and at a low cost, and the sensitivity difference of the sensor unit is a sound having a predetermined frequency and magnitude, Alternatively, measurement and comparison can be performed for each sensor unit using a reference signal source that emits vibration, and optimal correction can be made. Therefore, any sensor unit can be used freely when measuring abnormal noise. , An allophone measurement tool that realizes high-precision measurement by correcting sensor sensitivity differences in a short time, easily and accurately is realized.

FIG. 1 is a schematic circuit diagram of an abnormal sound measuring tool according to the present invention. Reference numeral 1 denotes an abnormal sound measuring tool body, and 3 denotes a sensor unit. Reference numeral 4 denotes a sensor for detecting abnormal sounds such as a microphone and an acceleration sensor. The output signal of the sensor unit is amplified by the main amplifier circuit 6 and digitally converted by the A / D converter circuit 7 and spectrum converted by the fast Fourier transform circuit 8. Then, the analysis process is performed 9 times and the result is displayed on the display function 10. FIG. 2 is different from FIG. 1 in that the sensor unit 2 includes a sensor 4 and a sensitivity correction amplification circuit 5, and is a configuration generally used conventionally.

In the configuration of FIG. 2, since the sensitivity correction of the sensor unit is performed by adjusting the gain of the sensitivity correction amplification circuit 5, adjustment and inspection of the sensor unit are necessary. After adjustment, the sensor 4 and the sensitivity correction amplification circuit 5 are integrated. It cannot be separated. In addition, the number of parts is high and the cost is high, and the shape is large, which is greatly inferior to that shown in FIG. In the configuration of FIG. 1, the sensor unit 3 has a simple configuration in which the sensor 4 is mounted on the sound collection piece. When the sensor unit 3 is replaced with an arbitrary sensor unit, the signal received by the sensor unit from the reference signal source is the main body of the abnormal noise measurement tool. The gain setting may be performed in the main amplifier circuit 6 configured to 1 so that the input of the A / D conversion becomes a predetermined level. The input level of A / D conversion is confirmed by displaying the digital output 11 of the A / D conversion circuit 7 with a display function 10 such as an LCD.

FIG. 3 shows a schematic diagram of the circuit configuration of the reference sound source 19. The output of the sine wave generation circuit 14 having a predetermined frequency is amplified by the speaker amplification circuit 13, and a reference sound is emitted from the speaker 12. The sensor unit collects sound, and the cable 18 connects to the abnormal sound measurement tool body. FIG. 4 is a conceptual diagram of the configuration of FIG. 3. Since the reference signal source 19 is separated from the abnormal noise measurement tool main body and is configured to be portable with the battery 15, the abnormal noise measurement tool used by being installed in various places is used. Bring it close to the main unit and check and correct the sensitivity of the sensor unit when necessary. The reference signal source can be configured integrally or detachably without being separated from the abnormal sound measurement tool body. In this way, by attaching an optional sensor unit to the abnormal noise measurement tool body and correcting the sensor sensitivity difference in a short time, easily and accurately, the measurement error of abnormal noise can be prevented, and The high-accuracy abnormal noise measurement tool that realizes the maximum use of the display function that is basically provided as a measurement tool and at the lowest cost is realized.

The sound collection piece 16 is formed with an exponential curve on the inner surface, is made of high specific gravity brass with high sound reflectivity, height: 3 cm, bottom diameter: Φ3 cm, thickness 2 mm, sensor 17 is a condenser microphone It was used. The speaker 12 was set to have a diameter of 35 mm, a standard frequency of 1.5 KHz, and a volume of 60 dB. The reference signal source 19 was configured to have a size of length × width × height = 60 × 60 × 50 mm. The sensor is not limited to a microphone, and may be an acceleration sensor. The dome-shaped material may be a high specific gravity material such as stainless steel. In addition, FFT conversion, arithmetic processing, display tools, etc. may not be individually configured by hardware, but a personal computer may be used, and the reference signal source is not limited to a sine wave, 1.5 KHz. Various configurations such as integration, separation, and attachment / detachment are possible. Further, various means for displaying the input level of A / D conversion are conceivable, such as an LCD and an LED, but it is desirable to use a display function used by the noise measurement tool. Further, by confirming how the result of the FFT conversion of the signal from the reference signal source is displayed in the spectrum, it can be used for confirming the operation of the entire noise measurement tool. Various functions, configurations, dimensions, materials, and the like are not limited to the present embodiment, and various modifications can be made without departing from the spirit of the present invention.

1 is a schematic diagram of a circuit configuration of an abnormal sound measurement tool according to the present invention. A schematic diagram of a circuit configuration of a general noise measurement tool is shown. A schematic diagram of a circuit configuration of a reference signal source is shown. The block diagram of a reference signal source is shown.

DESCRIPTION OF SYMBOLS 1 Abnormal noise measuring tool body 2 General sensor unit 3 Sensor unit applied to this invention 4 Sensor 5 Sensitivity correction amplifier circuit 6 Main amplifier circuit 7 A / D converter circuit 8 FTT
9 Analysis processing circuit 10 Display function 11 A / D digital output 12 Speaker 13 Speaker amplification circuit 14 Sine wave generation circuit 15 Battery 16 Sound collection piece 17 Microphone 18 Cable 19 Reference signal source

Claims (3)

A sensor unit equipped with a sensor such as a microphone picks up abnormal noise and ambient noise of the device under measurement, amplifies it with an amplification circuit, converts it into a digital signal through A / D conversion, and converts the frequency spectrum through fast Fourier transform (FTT). In an abnormal sound measurement tool that performs analysis processing, each sensor unit does not have individual sensitivity correction means, and a gain is set for a reference signal source that emits a sound or vibration having a predetermined frequency and magnitude, or the output signal of the sensor unit. An amplifier circuit that inputs to the A / D conversion circuit, and a display function that displays the input level of the A / D conversion, and an amplifier circuit that picks up the signal picked up from the reference signal source by the sensor unit attached to the noise measurement tool By adjusting the gain and setting to input to the A / D conversion at a predetermined level, any sensor The unit, in a short time, easily, accurately, allowing measurement with high accuracy by correcting the sensitivity difference, abnormal noise measurement tool. The abnormal sound measurement tool according to claim 1, wherein a reference signal source that emits a sound having a predetermined frequency, loudness, or vibration is configured separately from the abnormal sound measurement tool. The abnormal sound measurement tool according to claim 1, wherein a reference signal source that emits a sound having a predetermined frequency, loudness, or vibration is configured to be detachable from the abnormal sound measurement tool.

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