JPS6017378A - Ultrasonic measuring device - Google Patents

Abstract

PURPOSE:To measure a snow depth, a water level, or the like with high precision without causing an error due to the variance of atmospheric temperature by providing the second head, and measuring two kinds of reflection time to correct the error. CONSTITUTION:When a control part 20 generates a tone burst of a sine wave from a turn burst generator 12 as ''continuous'', a ultrasonic wave is radiated from the first head 1 through a transmitting amplifier 13 and a shared circuit 14. After a while, radiated ultrasonic wave is reflected on an object 7 to be measured and are returned to the first head 1 and the second head 2 successively. The wave received by the first head 1 and the second head 2 are amplified by receiving amplifiers 15 and 16 and appear in comparators 17 and 18. If levels after the amplification of intensity of received wave in amplifiers 15 and 16 exceed the output of a slice level circuit 19, comparators 17 and 18 output the output. This output is received by the control part 20 to obtain the time from radiation. On a basis of this time, the control part 20 obtains a depth in accordance with a formula and outputs it as a digital code to an output 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for measuring depth, etc. using ultrasonic waves, and is capable of accurately measuring depth.

Measuring the water level of a dam or the depth of snow by the propagation time of ultrasonic waves has been practiced for a long time.

In this case, it is necessary to correct the measured value based on the sound wave propagation time due to changes in temperature, and error correction using a thermometer has been common. When using a thermometer, the thermometer itself is an analog signal, and it is difficult to reduce errors.

The present invention enables highly accurate measurement by providing a second head, measuring the reflection time in two ways, and correcting errors.

One embodiment of the present invention will be described below with reference to the drawings. Fig. 1 shows the installed state of this device. The first head 2 receives the sound waves reflected from the measuring object 7 and converts them into electrical signals, and the second head 3 receives the sound waves reflected from the measurement object 7 and converts them into electrical signals. A support rod that holds the second head 2 at a certain distance apart from the first head 2 and the second head 2 at a certain distance. Both the second head 2 is attached facing the measurement target. Reference numeral 4 denotes a main body that houses the electric circuit portion of this device, the details of which will be described later. Reference numeral 6 is a pole made of concrete, steel pipe, etc., to which this device is attached, and 6 is a base such as the bottom of a cylinder for a water level gauge, or the ground for a snow gauge. 7 corresponds to objects to be measured such as depth and height; water level corresponds to water; snow depth corresponds to snow, etc.

Fig. 2 is a block diagram showing the electrical configuration of this device in detail.
12 is a tone burst generator that continuously oscillates the output sine wave of the oscillator 11 (for example, 2
The intermittent time is determined by the control unit 2.
Control with Q. 13 is an amplifier that amplifies the signal generated by tone burst generator 12 to a predetermined level; 14 is an amplifier that amplifies the signal generated by tone burst generator 12 to a predetermined level;
A shared circuit for sharing the first head 1 for transmission and reception;
15 is a receiving amplifier that amplifies the electrical signal of the sound wave received by the first head 1; 16 is a receiving amplifier that amplifies the electrical signal of the sound wave received by the second head 2; 17 and 18 are receiving amplifiers; A comparator 19 determines whether the outputs of the wave amplifiers 15 and 16 exceed the slice level, and 19 is a comparator 18.1.
This slice level circuit determines the slice level of No. 9, and outputs an electrical output corresponding to the slice level designated by the control unit 2°. 2o determines the intermittent time of the tone burst generator 12, and the emitted ultrasonic wave is reflected and the first
Head 1. Time t1 until returning to the second head 2
and a control unit that measures t2, calculates the depth from this, determines the slice level, and outputs the measurement results. In this case, it is now preferable to use a microcomputer for the control section 2o.

Also, the reflection time t1. t2 starts from the moment the tone burst generator 12 is set to "continue" by the control unit 20.
It is measured as the time until the output of 5.16 exceeds the output of the slice level circuit 19 and the comparison output appears in the comparator 17.18.

Now, the first head 1. Assuming that the height of the base 6 of the second head 2 is Hl and H2, the depth of the object 7 to be measured is V, and the speed of sound is V, the reflection time of the two is t1=2 (Hl-h)/v For immediate use -=・(1)t
2=C(Hl-h)+(H2-h))/v-
times (2), and therefore. The control unit 20 performs this calculation. In this formula,
Hl and H2 are given as constants when installing the equipment.

(It is stored in the control unit 1.) Reference numeral 21 is the output of the control unit 2°, which outputs a signal indicating the depth using a digital code.

In such a device, when the control section 2o generates a sine wave tone burst in the tone burst generator 12 as a "continuation", the transmission amplifier 13. Through the shared circuit 14,
Ultrasonic waves are emitted from the first head 1. After a while, the emitted ultrasonic waves are reflected by the measurement object 7, and the first head 1. Return to the second head. 1st head 1
．． The received wave from the second head 2 is amplified by receiving amplifiers 15 and 16 and appears at comparators 17 and 18. When the strength of the received wave exceeds the output of the slice level circuit 19 at the level after being amplified by the amplifiers 15.16, an output is output to the comparators 17.18. The control unit 2o captures this and calculates the time since the firing. Based on this time, the control unit 20 uses equation (3)! l
l depth is determined and output as a digital code to the output 21.

In the above description, it is assumed that the first head 1 and the second head 2 are placed perpendicularly to the object to be measured, but this apparatus does not necessarily need to be placed vertically. In this case, if the depth is tilted by t from the vertical, the depth will be obtained by multiplying h in equation 3 by CO8θ, so this calculation will be added to the control unit 200 function.

In addition, in this explanation, the first head 1 is used for both transmission and reception, but
Instead of the first head 1, it is also possible to use two heads and make them separate heads for transmission and reception.

As described above, according to the present invention, snow depth, water level, etc. can be measured with high accuracy without causing errors due to changes in temperature.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an ultrasonic measuring device according to an embodiment of the present invention, and FIG. 2 is a block diagram thereof. 1.2... Head, 11... Oscillator,
12...Tone burst generator, 13...
...Transmission amplifier, 14...Shared circuit, 15.1
6... Receiving amplifier, 17° 8... Comparator, 19... Slice level circuit, 20...
...control section. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Claims] Two heads with different positions are installed at positions where they can receive the ultrasonic tone burst reflected waves from the surface to be measured, and the output of each head is added and compared with a commonly controlled slice level. An ultrasonic measuring device comprising: a comparator, and means for controlling the slice level and calculating the position of a surface to be measured from the outputs of both comparators.