SU437924A1 - Digital Automatic Elastic Wave Speed Gauge - Google Patents

Description

one

The invention relates to the field of measurement technology and is intended to study the physicomechanical properties of rocks by measuring the velocity of propagation of external waves in their environment.

A device comprising a control unit (reset to the initial state), a percussion unit, a seismic sensor, an amplifier, a threshold stage, a pulse shaper, an end stage with a coincidence circuit, and a time converter in the code are known.

However, the known device is characterized by low accuracy and the reliability of the results of measuring the properties of rocks by the method of elastic waves in a rock mass. The known device also does not provide for direct measurement of the velocity of elastic waves in the rock mass.

The known device is made two-channel, allowing to measure the speed of propagation of ultrasonic oscillations of only one area 0: the frequency between the two transducers. To determine the speed of wave propagation in several parts of the sample, additional time is required, and in determining it directly in the mountain massif, the large wave penetration is necessary. Since this device

uses ultrasonic waves with low penetrating power, it cannot be used to determine the speed of propagation of elastic

waves at significant distances in the mountain range. The absence of noise immunity in the presence of interference distorts the accuracy and reliability of the measurement results.

The aim of the invention is to determine the speed of propagation of elastic waves directly in the rock mass, for several sections of the profile at the same time and improving the accuracy and reliability of the obtained

measurement results.

This is achieved by introducing a frequency filter between the seismic sensor and amplifier, an amplitude field filter with an interference indicating unit and an amplitude noise filter setting — a small amplifier and a threshold cascade;

connected to the final stage, and the interference indication unit, between the time-to-code converter and the control unit. The speed meter contains n such channels with common for all channels blocks of equilibrium, spd | ikan.i nomekhi, shock block and the generator of counting pulses. The drawing shows a block diagram of the proposed digital meter. Digital automatic speed meter consists of n parallel channels. Each channel is composed of a seismic sensor 1, a frequency filter 2, an amplifier 3 in limiting mode, a filter 4 amplitude sensors with a block 5, a disturbance in the channel and an amplitude interference filter setting, a threshold stage 6, a generator of the forcing 7 of the pulse 10, a linear distributor 8, the battery stage 9, the generator 10 counting pulses, the converter 11 time intervals in the code, the printing device 12, the noise indication display unit 13 in the process of speed measurement, the start control unit 14. The launch of uirughi oscillations is carried out by a pulsed source of urughi waves-shock unit 15 located in the mountain massif 16. The studied section of the massif 16 is broken down into separate profiles, along which the seismic sensors 1 are set at a constant step. The sound frequency waves are excited by a shock unit 15 . Seismic sensor 1 converts oscillations of mountain rocks into electric sigals that pass through frequency filter 2 interference and are amplified by amplifier 3. To increase the steadiness of the first oscillation amplitude and the smaller influence of this front on the accuracy of indication 3, when amplifying oscillations, it operates in the amplitude limiting mode . The signal from the output of amplifier 3 is supplied by a 4 amplitude noise filter 4, which is configured in such a way that no sigals interfere with the signal, which are similar in frequency to the useful signal, and oo less than its amplitude. Then the useful signal arrives at the block 5 for displaying the noise and for adjusting the filter 4 amplifiers and for the threshold stage 6, which gives a square pulse at the moment of arrival of the useful signal. The reference pulse shaper 7 outputs a short triangular pulse to the input of the linear distributor 8 along the leading edge of the rectangular pulse of the threshold stage 6. The reference pulses from all n channels of the reference pulse shaper 7 start the linear distributor 8 sequentially. At the outputs of the distributor 8 rectangular pulses are received , the duration of each of which is proportional to the time interval between two subsequent reference pulses (i.e. the time of wave propagation from the sensor to the dates CGI). The rectangular pulses from the outputs of the distributor 8 are fed to one of the inputs of the final stage 9 (schemes “I”). The second input of the final stage 9 receives triangular pulses from the heater 10 counting pulses. Thus, the number of pulses on the input of each end stage 9 is proportional to the corresponding duration of them, the zero from the output of the distributor 8. The converter 11 time intervals to the code converts the number of pulses of the corresponding time interval to a code that characterizes the speed of the elastic wave and delivers, for example, on a digital scoreboard or recorded by a printing device 12 pa paper tape. The launch control unit 14, before each measurement, initializes threshold stages 6 and time slots converters 11 into a code, and then issues a command to start a pulse source of elastic will of the sound diarazon-percussion unit 15. Interference disturbance unit 13 in case of interference similar to amplitude and frequency with a usable sigal, prohibits their indication on the digital display board of the converter 11 and recording the readings on the printing device 12. After disabling the indications, the display unit 13 issues a 1 command to the control unit 14 to start th a re-measurement process. After this, the control unit 14 removes the prohibition from showing, issuing the corresponding command to the display unit 13. This process takes place automatically before the occurrence of measurement results on digital boards and a printing device 12. Subject of the invention 1. A digital automatic elastic wave velocity meter containing a serially connected control unit, a shock unit, a seismic sensor, an amplifier, a threshold stage, a pulse shaper, and an end stage and a time slot converter in the code, distinguished by the fact that, in order to increase the accuracy and reliability of the measurement results, a frequency filter was inserted into it p between seismic sensor and amplifier, amplitude interference filter with interference indication unit and amplitude interference filter settings between amplifier and threshold stage, linear distributor between pulse shaper and terminal stage, counting pulse generator connected to the final stage, and display unit .mehi between a time-to-code converter and a control unit, also connected to the threshold stage and a time-to-code converter. 2. The speed meter according to claim 1, characterized in that, in order to directly determine the speed of propagation of elastic waves in the mountain massif, it contains 3 n identical channels. With common channels by control units, for all interference, the shock unit and the counting pulse generator . 437924 4

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