CS205058B2 - Device for addition and measuring the time of electric signals mainly for adition and measuring the time of seismic signals - Google Patents

Description

BACKGROUND OF THE INVENTION The invention relates to a device for adding and measuring the time of electrical signals, in particular for adding and measuring the time of seismic signals, comprising a data acquisition and data acquisition unit controlled by a control unit cooperating with a delay unit and a display unit.

The device is particularly useful for measuring the parameters of the subsurface zone of soil plunged to the surface during a seismic survey.

To date, several additions and time measurements of electrical signals have been performed using an analog counter on continuous signals. Then, after conversion to the digital form, the sum of the signal values is written to the appropriate memory cells, while one of the signals is read from a particular memory cell and converted to an analog form, then added to the signal from the sensor in the analog counter and then converted is written as a sum to the same memory cell. Such an addition of signals brings an error resulting from the principle of operation of analog units.

From Polish patent no. 81521 is also known a seismic time value measuring device which only allows time measurement without the possibility of adding and accumulating a seismic signal. Measurements of the low speed zone performed by said apparatus require the use of complex and expensive field work methods. It is necessary to drill a hole and use explosives, which brings other difficulties.

These disadvantages are eliminated with the device according to the invention, in which the addition and acquisition unit comprises a digital adder to which an analog-to-digital converter is connected, as well as a memory provided by the control unit, and a digital-to-analog converter, the unit consists of a bidirectional counter with programming set by the time delay selector and a time display unit coupled to the bidirectional counter via a buffer and is further provided with a time marker unit coupled to the bidirectional counter.

The invention makes it possible to measure the travel time of a seismic wave between a source of vibration excitation and a sensor, which is generally a geophone. The excitation source may even be a low power mechanical device, eliminating the use of the explosives used so far, which are usually placed in boreholes. Given the ability to sum the electrical signals obtained from the geophone from the seismic wave excitation in succession without any change in the position of the geophone and the excitation location, it is possible to separate the selected useful seismic wave from the microseismic waves and interference. The melt multiplication factor 208058 is determined based on the observation of the seismic wave stored in the memory and transmitted to the screen of the screen, whereby an optional display time of the signal image can be obtained. It is also possible to use the device according to the invention as an oscilloscope for observing analog signals, in particular aperiodic signals. Moreover, the device finds its application in the testing of soil mechanics for the needs of civil engineering.

An embodiment of an apparatus for counting and measuring the time of electrical signals according to the invention is shown in the accompanying drawings, in which Fig. 1 is a block diagram of a device for counting and measuring the time of electrical signals, in particular for counting and measuring the time of seismic signals. Fig. 3 shows a block diagram of the addition and collection unit of the device;

shows visually the principle of seismic wave time measurement.

The apparatus for counting and measuring the time of the electrical signals of FIG. 1 consists of a data acquisition and data acquisition unit 1 controlled by a control unit 2 which cooperates with the delay unit 3 and a display unit 4 connected to the data acquisition and data acquisition unit 1 and 3. The signal source comprises a sensor, preferably a geophone 5, connected by a data acquisition and data acquisition unit 1.

The data acquisition and data collection unit 1 of FIG.

it consists of a digital adder 6 which receives electrical signals in digital form, one signal coming from an analog-to-digital converter 7 to which one analog signal is supplied from the geophone 5 by an input amplifier 8 and the other signal coming from a memory 9 connected to the control a memory unit 10 and a digital-to-analog converter 11.

The delay unit 3 consists of FIG.

from the bidirectional counter 12 with the programming set by the time delay selector 13, and from the time display unit 14 connected to the bidirectional counter 12 via a buffer 15. Furthermore, the delay unit 3 is provided with a time tag 16 cooperating with the bidirectional counter 12.

The addition and measurement of the time of the seismic signals is performed as follows. The trigger signal generated in the control unit 2 triggers the delay unit 3, which delays the start of addition and data acquisition in the addition and data acquisition unit 1 by a delay value 17 (FIG. 4), predetermined by the time delay selector 13. After the delay 17 has been measured, the delay unit 3 initiates the addition and acquisition of data by the control unit 2. The control unit 2 sends commands to the analog-to-digital converter 7 contained in the addition and data acquisition unit 1 to perform analog-to-digital conversion of the signal 18 from the geophone 5. in an input amplifier 8 connected to the input of the addition and collection unit 1. Simultaneously with the conversion command, the control unit 2 sends a command to read the data from the memory 9, which data is sent directly to the digital adder 6, in which the data is added together with the data resulting from the analog-to-digital signal conversion. The signal addition process is performed identically for all memory cells 9.

The counting process is terminated by a command sent by the control unit 10, which is transmitted to the control unit 2. This is simultaneously the signal for displaying data on the screen 19 contained in the display unit 4. The counting procedure is repeated several times. repeats until a satisfactory result is obtained, which is determined by the image on the screen 19. In the image of the seismic signal 18 shown in Fig. 4, shown on the screen of the screen 19, the mark 20 is superimposed to determine the time 21 elapsed since the time 22 of the seismic wave excitation until the time indicated by the indicated mark 20 on the seismic signal 18 is displayed on the screen 19. The amount of time between the time 22 and the mark 20 is displayed in the time display unit 14 (FIG. 3).

Claims (1)

SUBJECT Apparatus for adding and measuring the time of electric signals, in particular for adding and measuring the time of the seismic signals, consisting of a data acquisition and data acquisition unit controlled by a control unit cooperating with a delay unit and a display unit, characterized in that the unit (1) the data acquisition and acquisition comprises a digital adder (6 j) to which an analog-to-digital converter (7) is connected, as well as a memory (9) provided with a control OF THE INVENTION and a digital-to-analog converter (11), the delay unit (3) consisting of a bidirectional counter (12) with programming set by a time delay selector (13) and a time display unit (14) associated with the bidirectional counter (11). 12) via a buffer (15) and further provided with a time marking unit (16) connected to a bidirectional counter (12).