SU977778A1 - Device for measuring time of propagation of elastic waves in rock mass - Google Patents

Description

The invention relates to mining and to be used to estimate the stress state and to study the properties of the rock mass. A device for determining the time of propagation of elastic waves in a rock mass is known, comprising sensors-, generator, time relay, main reversible counter and display unit C1. A disadvantage of this device is the large measurement error. A device is known for determining the propagation time of elastic waves in a rock mass, containing two sensors whose outputs are connected via amplifiers to time relay inputs, the third input of which is connected to the generator output, and through the first OR element to the counting input of the first reversible counter. , the control input of which is connected to the trigger output, and the code output to the input of the display unit, the second OR element, whose inputs are connected to the outputs of the respective amplifiers, and the output through the differential disk iminator - to one of the outputs of the first element I, the other input of which is connected to the generator output, the second reversible counter, the control input of which is connected to the second output of the differential discriminator through the key generator, and the output to one of the trigger inputs, and the second element And, the inputs of which are connected to the outputs of the generator and the trigger and the output to the second input of the first element OR 2. The drawback of the device is the complexity of the design, as well as a large measurement time + to t where 1iz; m + time required to form and code corresponding to the measuring error, which must be compensated; the time required for the second meter to operate in the reverse mode, in which the information in it is counted to 0. The purpose of the invention is to reduce the measurement time and simplify the design of the device. The goal is achieved by

that the device contains two sensors, the outputs of which are connected via amplifiers to the inputs of a time relay, the third input of which is connected to the generator output, and the% output through the first OR element to the counting input of the first reversible counter, the control input of which is connected to the trigger output, and the code output with the input of the display unit, the second OR element, whose inputs are connected to the outputs of the respective amplifiers, and the output through the differential discriminator to one of the inputs of the first AND element, the other input of which is connected with the generator output, the second, a reversible counter, the control input of which through the key is connected with the second output of the differential discriminator, and the output with one of the trigger inputs, and the second element I, whose inputs are connected to the outputs of the generator and trigger, and the output with the second input of the perforated element OR, the first output of the differential discriminator is connected to the second input of the trigger, and the output of the first element I to the estimated input of the second reversible counter.

Figure 1 shows the block diagram of the device; Fig. 2 shows timing diagrams explaining its principle of operation.

The device contains sensors 1 and 2 amplifiers 3 and t, time relay 5, generator 6, elements OR 7 and 11, indication unit 10, differential discriminator 12 consisting of threshold elements 17 and 18, element OR 19 and key 20, main reversing counter 8, trigger 9, elements And 13 and 1, the second reversible counter 1 and the forming key 15.

The outputs of sensors 1 and 2 through amplifiers 3 and +, respectively, are connected to the inputs of time relay 5, the third input of which is connected to the output of generator 6, and the output through element And 13. The other input of element And 3 is connected to the output of generator 6, and the output with counting the output of the reversible counter 14. The control input of the counter 14 via the generating key 15 is connected to the second output of the differential discriminator 12, and its potential output is connected to another output of the trigger 9.

The outputs of the element And 1B are connected to the outputs of the generator 6 and the trigger 9, and its output - with the second output of the element OR 7The device works as follows.

The signal from the sensor 1 after amplifying the amplifier (3 of Fig. 2), first, turns on the relay 5 times (the relay turns on with delay, because it has a certain

Q threshold of sensitivity (Fig. 2g), as a result of which the clock pulses of the generator 6 through the indicated relay and the OR element 7 begins to arrive at the counting input of the reversing counter 8, which is working at the beginning of the measurement cycle in the addition mode (q2-2 and, secondly, is fed through the OR 11 element to the differential discriminator 12, causing the threshold elements 17 and 18 of the lower U- and upper U levels to operate sequentially, respectively. When triggered, the threshold elements form pulses that pass through the OR 19 element to the key 20, with an output to An orthogonal pulse is taken equal to the duration of the rising edge of the signal at point A (Fig. 2b). This pulse is applied to the control input of the And 13 element and opens it for a time equal to the duration of the pulse. 6 begin to fill the reversing counter 14, which at the beginning of the cycle

Claims (2)

measurement works in the mode of addition (figv). At the time corresponding to the triggering of the threshold element 18 of the upper level of the segment OR 7 to the counting input of the reversible counter 8. The control input of the counter 8 is connected to the output of the trigger 9 and its code output to the input of the display unit 10. The output of the element OR 11 is connected to the input of the differential discriminator 12. One output of the differential discriminator 12 is connected to one of the outputs. the trigger 9 and the electric switch at the point L, which forms the key 15, generates a pulse (Fig. 2d), which is fed to the control input of the reversing counter 1 and transfers it to the countdown mode, i.e. to the subtraction mode, (which starts later - with the arrival of the next burst of impulses from the output of the element E 13). The signal from sensor 2 after amplification by an amplifier (FIG. 2a), first, turns on the time relay (figure 2). as a result, the arrival of clock pulses to the reversible control unit 8 is temporarily stopped (Fig. 2d), and, secondly, is applied through the OR element 11 to the differential discriminator 12, causing the lower and upper levels threshold elements 17 and 18 to be triggered and the output of the key 20 is a rectangular pulse equal in duration to the time t of the rising edge of the signal at point B (Fig. 26). This impulse reopens the element I 13, through which the clock pulses of the generator 6 begin to arrive at the counting input of the reversible counter 14 (FIG. 2B). The content of the latter is reduced (since the counter was previously transferred to the subtraction mode) and after a time equal passes through zero value (1; 1 t) (t;, t). At this moment, the signal O from the potential output of the reversive counter 1HF (2d) sets the trigger 9 to position 1. (Figure 2e). A cycle of ut measurement error correction begins. The leading edge of a pulse from a single trigger output, the reversible counter 8, is transferred to the counting mode, while the reversible counter 1 continues to operate, counting the clock pulses. By the end of the clock cycle, a code proportional to h1 will be written in it. At the same time, the element AND 16 and the clock pulses of the generator 6 over the elements AND 16 and OR 7 are opened again to the counting input of counter 8, whose content is reduced by an amount proportional to the difference between the time the rise of the output signals of the sensors 1 and the falling edge of the rectangular pulse from the output of the key 20, the flip-flop returns to the initial position O, the flow of the clock pulses of the generator 6 to the reversible counter b stops and the cycle korretsii error measurement terminates .In reversing schechtike 8 remains code that displays the true value of the propagation time of the elastic wave in mlssive rocks. The proposed device allows to reduce the measurement time to f 1 em + 12 and to simplify the design of the device by reducing the number of generating keys and OR elements. The invention The device for determining the propagation time of elastic waves in a rock mass containing two sensors whose outputs through amplifiers are connected to time relay inputs, the third input of which is connected to the generator output, and the output through the first OR element to the counting input of the first reversible counter whose input is connected to the trigger output; and the code output with the input of the display unit, the second OR element, whose inputs are connected to the outputs of the respective amplifiers, and the outputs via the differential discriminator to one of the inputs of the first And element, the other input of which is connected to the generator output, the second reversible counter, the input of which is connected with the second output of the differential discriminator through the key generating unit, and the output with one of the trigger outputs, and the second element I, whose inputs are connected to the outputs of the generator and the trigger, and the output with the second input th first OR gate, characterized in that in order to reduce measurement time and uprschtseni device structure, the first output of the differential discriminator is connected to the second input of the flip-flop, and the output of first AND - schetonomu to the input of the second down counter. Sources of information taken into account in the examination 1. The author's certificate of the USSR (f 76531, cl. G 01 N T / C, 1975. 2. USSR author's certificate №, cl. E 21 C 39/00, 1977 (prototype). FIG. I