JPS5815105A - Ultrasonic wave thickness gage - Google Patents

Abstract

PURPOSE:To obtain a thickness gage of pocket type which can display the thickness of a specimen in terms of figures and bottom shape by providing a position signal generating part in an ultrasonic probe part and providing a flat platelike display board in a digital thickness display part. CONSTITUTION:The ultrasonic waves 4 emitted in a specimen 3 by a pulser 1 and a probe 2 are reflected by a bottom surface 5, and said waves received by a probe and are inputted via a waveform forming circuit 7 via an FF circuit 9 which is applied with the signal of the pulser 1 with delay 8. After the waves are integrated 11, they are subjected to A-D conversion 12, and the thickness is displayed on a digital display device 14. The thickness signal after A-D conversion 16 is inputted to analog switches 17. The ultrasonic waves from a microphone 18 are picked up with a microphone 20, and the time difference between both microphone signals is detected 22 and is made into a position signal for the probe. The switches 17 are selected sequentially by said signal, whereby the thickness signal is stored as the bottom shape of the specimen in each position of the probe in a max. value holding circuit 23 consisting of shift registers and said shape is displayed in a two-dimensional display circuit 24.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic thickness meter, and particularly to a thickness meter suitable for displaying the thickness and bottom shape of a subject.

Conventional pocket-type ultrasonic thickness gauges only display numbers, and none display thickness and bottom shape.

In addition, there are devices that display the thickness as a cross-sectional shape that are a combination of a conventional ultrasonic flaw detector and a storage cathode ray tube (CRT) device, which can display the bottom shape, but this is not possible with a pocket Compared to the mold thickness gauge, it was large and inconvenient to carry.

The present invention eliminates the above-mentioned drawbacks and provides a pocket-type ultrasonic thickness meter that can display the thickness of a subject in terms of the bottom shape and numbers.

The present invention provides a position signal generating section in the ultrasonic probe section and a flat display panel in the thickness display section to display the bottom shape and thickness of the object.

FIG. 1 is a block diagram of the ultrasonic thickness gauge of the present invention. l
Excites the pulsar ultrasonic probe 2r.

The ultrasonic probe 2 is placed on the subject 3, and the ultrasonic waves 4 generated by the ultrasonic probe 2 are reflected by the bottom surface 5 and are received by the ultrasonic probe 2. The received signal is amplified by an amplifier circuit 6 and shaped by a waveform shaping circuit 7. On the other hand, in synchronization with the excitation of the ultrasonic probe 2, a delay circuit 8 is output from the pulser 1.
The signal is sent to the flip-flop 9 and is applied to the flip-flop 9 with a slight delay.

The flip-flop 9 outputs a signal of 1'' from the delay circuit 8, and outputs a signal of 0'' from the waveform shaping circuit 7.

The range switching circuit is used when it is necessary to switch depending on the display range or thickness of the object, and changes the level of 1".

Integrating circuit 11 integrates the output of the range switching circuit and generates a sawtooth wave that changes over time. When the output of the integrating circuit 11 is led to the A/D converter and converted into a numerical display signal by the decoder 13, the thickness of the subject is displayed on the numerical display 14.
is shown. Further, the output of the integrating circuit 11 is led to a display range setting circuit 15, where only signals or signals above an arbitrary level are output.

Then, the A/D converter 16 converts the signal higher than an arbitrary level to the A/D converter 16.
The signal is converted into a digital signal and output to the analog switch 17.

Reference numeral 18 denotes a microphone for transmitting sound waves, which is attached to a microphone holder 19. A sound wave receiving microphone 20 receives sound waves from the sound wave sending microphone 18, and the signal is amplified by an amplifier circuit 2F and sent to a time measuring circuit 22. The time measuring circuit 22 determines the time difference between the signal to the sound wave sending microphone 18 and the signal from the sound wave receiving microphone 20, and outputs this signal to the analog switch 17. This time difference is the position signal of the ultrasound probe.

The analog switch 17 is provided corresponding to one axis of the flat plate-shaped secondary display circuit 24, and is selected and sequentially operated according to the position signal of the ultrasonic probe.

A maximum value holding circuit 23 composed of a shift register is connected to each analog switch, and the bottom shape of the subject at six ultrasonic probe positions is stored. Therefore,
This is achieved by displaying the output of this maximum value holding circuit on a two-dimensional display circuit.

FIG. 2 is a display example of a two-dimensional display circuit. FIG. 3 shows a case where the thickness is larger than the display surface, and the area surrounded by the display range 25 can be displayed completely. In this way, the display setting circuit 15 is used when setting the display range.

The present invention is a pocket-type ultrasonic thickness gauge with a bottom shape display function added. Although a flat two-dimensional display circuit is provided to display the bottom shape, the present invention also includes the use of a display device other than a liquid crystal display device as the display circuit. Although sound waves are used to detect the position of the ultrasonic probe, the present invention also includes the use of position detection means other than sound waves.

According to the present invention, the shape of the bottom surface of the object can be displayed using a pocket-type thickness gauge, which can greatly contribute to diagnosis of corrosion and prevention of destruction accidents in many fields including nuclear power plants, petroleum plants, etc.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the ultrasonic thickness gauge of the present invention.
FIG. 2 is an explanatory diagram of a display example of the two-dimensional display circuit of FIG. 1.

Claims (1)

[Claims] 1. In a thickness meter that transmits and receives ultrasonic waves and measures the thickness of a subject from the propagation time thereof, the probe section is provided with a position detection means, and the display section is provided with a flat two-dimensional display. 1. An ultrasonic thickness gauge characterized by being provided with means and numerical display means to display the bottom shape and thickness. 2. The ultrasonic thickness gauge according to claim 1, wherein a liquid crystal display device is used as the flat two-dimensional display means. 3. In claim 1, the ultrasonic wave is formed so as to display the shape of the bottom surface as an image without being scaled even in the case of a thick wall by varying the threshold level of the analog signal. Thickness gauge.