JPH02236449A - Ultrasonic measuring method and ultrasonic measurer for this method - Google Patents

Abstract

PURPOSE:To easily measure the acoustic velocity and the extent of acoustic attenuation of a sample by arranging plural ultrasonic probes for transmission as well as reception of ultrasonic pulses at equal distances from the sample to be measured. CONSTITUTION:A high voltage pulse is transmitted from a transmission part 2 of an ultrasonic measurer main body 1 to probes 10A and 10B to simultaneously drive probes 10A and 10B, and thereby, ultrasonic pulse signals Pa1 and Pb1 are transmitted from probes 10A and 10B respectively. The signal Pa1 from the probe 10A is transmitted through materials 11 to be measured and is received in a plane part 15 by the probe 10B. Simultaneously, the pulse signal Pb1 from the probe 10B is transmitted through materials 11 and is received in a plane part 14 by the probe 10A. Since reception signals obtained by probes 10A and 10B have the same phase, the signal transmitted from probes to a reception part 3 is Pa1+Pb1 where signals from respective probes are added. Thus, the acoustic velocity and the extent of acoustic attenuation of the sample are easily measured.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a novel method for measuring the speed of sound and/or the degree of sound attenuation in a sample using ultrasonic waves, and an ultrasonic measuring instrument for the same.

[Conventional technology and problems]

Conventionally, there have been reflection methods (one probe method) and transmission methods (two probe method) as methods for measuring the sound velocity and/or sound attenuation of a sample using ultrasonic waves. These methods will be explained below.

FIG. 5 shows the configuration of an apparatus using the reflection method. That is, 1 is an ultrasonic measuring instrument main body, which includes a transmitting section 2 and a receiving section 3. The output of the transmitting section 2 and the input of the receiving section 3 are connected in common, and a probe I which also serves as a transducer for transmitting and receiving is connected via a pulse input/output terminal 5.
Connected to O. This probe 10 is brought into contact with one flat portion l2 of a plate-shaped sample to be measured l1 (with a thickness of T).

Further, a trigger signal synchronized with the output from the transmitter 2 is sent to the trigger input terminal 9 of the oscilloscope 4 via the trigger terminal 6, and an output signal from the receiver 3 is sent to the oscilloscope 4 via the signal output terminal 7. They are respectively connected to signal input terminals 8.

The operation of the above-mentioned apparatus will be described below. In FIG.
An ultrasonic pulse signal is transmitted from the probe 10 by transmitting a high voltage pulse from the transmitter 2 to the probe 10 and driving the probe 10. Sample to be measured 1
The pulse signal P1 that has passed through the probe 10 is reflected by the opposing surface 13, and the signal R1 returns to the flat section 12, where it is received by the probe 10 and further reflected. This reflected signal P2 passes through the sample to be measured, is reflected again on the opposing surface 13, becomes a signal R2, and heads toward the flat portion 12. This kind of operation will be repeated until the signal attenuates in sequence, and this situation is shown in Figure 7, when the pulse signal train (multiple reflection signal) R'1,
Displayed as Rl2. In the figure, P is a signal corresponding to driving, and Rl1 and Rl2 are signals received by the probe 10. Further, t1 is a time interval determined by the sound velocity and thickness T of the sample 11 to be measured. The speed of sound and the degree of attenuation of the sample to be measured were measured by calculating from each wave height value and time interval read from these signal sequences and the value of the thickness T.

Further, FIG. 8 shows the configuration of an apparatus for the transmission method. That is, 1 is an ultrasonic measuring instrument main body, which includes a transmitting section 2 and a receiving section 3. The output of the transmitting section 2 is connected via a pulse output terminal 25 to a probe 20 which is a transmitting transducer. Further, a signal from a probe 30, which is a receiving transducer, is connected to the input of the receiving section 3 via a pulse input terminal 35. The probe 20 is attached to one plane part 12 of the plate-shaped sample to be measured 11 (thickness is T), and the probe 30 is attached to the opposing surface 13, which is a plane part opposite to the plane part l2. being contacted. Further, a trigger signal synchronized with the output from the transmitter 2 is sent to the trigger input terminal 9 of the oscilloscope 4 via the trigger terminal 6, and an output signal from the receiver 3 is sent to the oscilloscope 4 via the signal output terminal 7. They are respectively connected to signal input terminals 8.

The operation of this device will be described below. By transmitting a high voltage pulse from the transmitter 2 of the ultrasonic measuring instrument 1 to the probe 20 and driving the probe 20 in pulses, the probe 20 An ultrasonic pulse signal is transmitted from the The pulse signal that has passed through the sample to be measured 11 reaches the opposing surface l3, where it is received by the other probe 30. Hereafter, similar to the reflection method described above, this signal is transferred to the oscilloscope 4.
The sound velocity of the sample to be measured was mainly measured by reading the required value and adding the thickness T into the measurement.

However, in both methods, when the attenuation of the sample to be measured is extremely large, the received signal obtained is small as shown in Figure 7.
In particular, when measuring the degree of attenuation, the received signal train becomes smaller over time, making measurement difficult.

[Problem to be solved by the invention]

The purpose of the present invention is to solve the above-mentioned drawbacks by shortening the time interval between the obtained received signal trains, and at the same time obtaining a sufficiently large signal, so that the speed of sound and the attenuation of sound can be reduced even in a sample to be measured with a large amount of attenuation. The purpose of this study is to propose a new measurement method and apparatus for this purpose.

[Means to solve the problem]

In order to solve the above problems, according to the method of the present invention,
A plurality of ultrasonic probes for both transmitting and receiving ultrasonic pulses are placed on the sample to be measured at approximately equal distances from each other, and these ultrasonic probes are pulse-driven at the same time. The speed of sound and the degree of attenuation of the sample are calculated and measured from the output signal sequence obtained by adding the outputs of the probes and the distance between the probes.

The apparatus of the present invention also includes an ultrasonic probe for both transmitting and receiving ultrasonic pulses, a transmitter for driving the ultrasonic probe, and a transmitter for processing the output of the ultrasonic probe. An ultrasonic measuring instrument having a receiving section, which includes a plurality of ultrasonic probes for both transmitting and receiving functions, a transmitting section that pulse-drives these ultrasonic probes simultaneously, and each ultrasonic probe. and a receiving section that adds the outputs of the .

[Effect]

In this invention, a plurality of signals from a plurality of probes pulse-driven at the same time simultaneously reach other probes arranged at approximately the same distance from each other, and become received signals. Since these signals are added, a received signal with a high level corresponding to the number of probes can be obtained.

〔Example〕

Hereinafter, the present invention will be explained along with the drawings.

FIG. 1 shows the configuration of an apparatus that is an embodiment of the present invention. In the figure, reference numeral 1 denotes the main body of the ultrasonic measuring instrument, which includes a transmitting section 2 and a receiving section 3. The output of the transmitting section 2 and the input of the receiving section 3 are connected in common, and two probes with substantially the same characteristics, which also serve as transmitting and receiving transducers, are connected via two pulse input/output terminals 5A and 5B. It is connected to child 10A and IOB, respectively. These probes 10A and l? 3B- is a plate-shaped sample to be measured 11 (thickness is T)
are brought into contact with the opposing flat parts 14 and 15, respectively. Further, a trigger signal synchronized with the output from the transmitter 2 is sent to the trigger input terminal 9 of the oscilloscope 4 via the trigger terminal 6, and an output signal from the receiver 3 is sent to the oscilloscope 4 via the signal output terminal 7. They are respectively connected to signal input terminals 8.

Note that this example shows the case where the sample is solid and two probes are placed on the surface of the sample, but if the sample is liquid, two probes are placed on an appropriate support in advance. The probe is fixed at a predetermined distance, and the support is placed in the liquid (inside the sample).

The operation of this embodiment will be described below. In FIG.
By transmitting high voltage pulses to A and IOB and driving these probes 10A and IOB simultaneously,
Ultrasonic pulse signal P from the probe 10A and IOB
1 and Pbl are respectively transmitted. The probe 10
The pulse signal P0 from A is transmitted through the sample to be measured 11 and is received by the probe 10B at the flat portion l5. At the same time, the pulse signal Pbl from the probe 10B also passes through the sample to be measured 11 and is received by the probe 10A at the flat section 14. By the way, the received signals obtained by each of the probes 10A and IOB have exactly the same phase, so the signals from these probes transmitted to the receiving section 3 are the sum of the signals from each probe. That is, P10Pl,I. By the way, the two pulse signals transmitted from the probes 10A and 10B are also reflected by the respective opposing surfaces 14 and 15, and the signal R
become at and Rbl, proceed to the opposite plane again, and reach their respective original planes again? The signal R1+R b l which is received and added in the same manner as described above is extracted. At this time, reflection also occurs, and thereafter, reception and reflection are repeated on the two opposing plane parts until the signal attenuates and disappears. An example of the received signal sequence displayed on the oscilloscope 4 at this time is shown in FIG. In the figure, P is a signal corresponding to driving, and Rl1, R"2, Rl,... are signals received by each probe. Also, t2 is a time determined by the sound speed and thickness T of the sample to be measured 11. Each wave height value and time interval read from these signal trains, and the thickness T
The sound velocity and attenuation degree of the sample to be measured are measured by calculating from the values of . Here, the received signal sequence of this embodiment is as follows:
4 compared to that obtained with conventional methods, the time interval L! is halved, and the magnitude of the signal is doubled when a probe with the same sensitivity is used. In addition, P■, P0, Pa+
+P1, R0, R b l . . . are convenient signal names and do not represent the magnitude or sensitivity of the signal.

In the above embodiment, the case where two probes were used was described, but the number of probes is not limited to two, and may be three as shown in FIGS. 4(a) and (b). or four probes 10A, 10B, IOC, and 10D can be used by arranging them at equal distances (L). Figure 4 (
In the case of three probes shown in a), the apex position of the equilateral triangle,
In addition, in the case of four probes shown in FIG. 4(b), the structure becomes three-dimensional, and the probes are arranged in relation to the apex positions of a regular tetrahedron. In short, the method according to the present invention can be applied if the probes are arranged on the sample to be measured so that the distances between the probes are all approximately equal. In this case, if the sample to be measured is a solid, the shape of the sample to be measured is restricted, for example by making it into a triangular prism shape in order to place the probe on the surface of the sample, making it difficult to use. If it is a liquid, it is only necessary to put a group of probes arranged as shown in FIG. It can be applied. [Effects of the Invention] As is clear from the above description, according to the present invention, a plurality of ultrasonic probes for both transmitting and receiving ultrasonic pulses can be placed on a sample to be measured at substantially equal distances from each other. , these are pulse-driven at the same time, and the outputs of each ultrasonic probe are added, so the received signal sequence has half the time interval and is twice the number of probes used as compared to the conventional one. Therefore, even in a sample with large sound attenuation, it is possible to easily measure the speed of sound and the amount of sound attenuation of this sample.

[Brief explanation of drawings]

1 to 4 are diagrams according to the present invention. FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram explaining the operation, and FIG. 3 is a diagram of the obtained signal. The schematic diagram and FIG. 4 show explanatory diagrams related to other embodiments. FIG. 5 is a block diagram of a conventional device, FIG. 6 is an explanatory diagram of its operation, FIG. 7 is a schematic diagram of an example of signals, and FIG. 8 is a block diagram of another conventional device. 1... Ultrasonic measuring device, 2... Transmitting unit, 3...
Receiving section, 10A. ．． IOB, IOC, 100-... probe. On Co., Ltd. g1 with patent application 2 drawings 3E2t Hall 4I! ! ]3 Chapter 6e21

Claims (2)

[Claims] (1) Place multiple ultrasonic probes for both transmitting and receiving ultrasonic pulses on the sample to be measured at approximately equal distances from each other, pulse-drive these ultrasonic probes at the same time, and A measurement method that calculates and measures the sound speed and attenuation degree of a sample from an output signal sequence obtained by adding the outputs of an ultrasonic probe and the distance between the probes. (2) An ultrasonic measuring device having an ultrasonic probe that can transmit and receive ultrasonic pulses, a transmitter that drives the ultrasonic probe, and a receiver that processes the output of the ultrasonic probe. A transmitting unit having a plurality of ultrasonic probes for both transmitting and receiving functions and driving the ultrasonic probes simultaneously in pulses;
An ultrasonic measuring instrument characterized by having a receiving section that adds the outputs of the respective ultrasonic probes.