CN115826044A - Construction method, device and system of seismic ground resistivity acquisition module - Google Patents

Abstract

The disclosure provides a construction method, a construction device and a construction system of a seismic ground resistivity acquisition module, relates to the field of seismic surveying, and particularly relates to the seismic ground resistivity acquisition module which can be applied to prediction of a large earthquake which possibly occurs in the future. The specific implementation scheme is as follows: the earthquake ground resistivity measured signal is accessed to a signal conditioning circuit to carry out impedance transformation and signal amplitude limiting, and a signal obtained by the impedance transformation and the signal amplitude limiting is transmitted to an analog-to-digital conversion circuit; the analog-to-digital conversion circuit converts the earthquake ground resistivity detected signal into a digital signal and transmits the digital signal to the signal isolation circuit; the signal isolation circuit is used for isolating a power supply and the ground used by the earthquake ground resistivity detected signal and the digital state signal in the earthquake ground resistivity acquisition module and sending the digital state signal to the main control circuit; the master control circuit controls the communication circuit to transmit the digital state signal to an upper computer for data processing. The anti-interference capability is enhanced, and meanwhile, the effect of measuring the precision of signals is improved.

Description

Construction method, device and system of seismic ground resistivity acquisition module

Technical Field

The present disclosure relates to the field of seismic surveying, and more particularly to a seismic ground resistivity acquisition module.

Background

The induction and the occurrence of the earthquake are a complex process, wherein the earth resistivity of the earthquake is one of the electrical parameters of the earth, and the earth resistivity method of the earthquake is an important earthquake monitoring and predicting means. The earthquake ground resistivity is obtained by continuously measuring the earthquake ground resistivity at a fixed place, researching the change rule of the ground resistivity of the earth surface medium along with time, searching the possible association between the normal change and the abnormal change of the earthquake ground resistivity and the abnormal change and the earthquake activity, and predicting the earthquake which possibly occurs in the future. But the problems of serious interference caused by surface factors and insufficient channels exist in the process of acquiring the earth resistivity of the earthquake at the present stage.

Disclosure of Invention

The technical problem to be solved by the present disclosure is to provide a method, an apparatus, and a system for constructing a seismic ground resistivity acquisition module, aiming at the defects existing in the prior art.

The utility model provides a construction method of a seismic ground resistivity acquisition module, which is characterized in that the seismic ground resistivity acquisition module comprises a signal conditioning circuit, an analog-to-digital conversion circuit, a signal isolation circuit, a main control circuit and a communication circuit; the signal conditioning circuit is connected with the analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is connected with the signal isolation circuit; the signal isolation circuit is connected with the main control circuit and the communication circuit; the earthquake ground resistivity acquisition module also comprises an alarm circuit, and the alarm circuit is connected with the main control circuit;

wherein the content of the first and second substances,

the signal conditioning circuit is used for receiving the earthquake ground resistivity measured signal, performing impedance transformation and signal amplitude limiting on the received earthquake ground resistivity measured signal, and then transmitting a signal obtained through the impedance transformation and the signal amplitude limiting to the analog-to-digital converter;

the analog-to-digital conversion circuit is used for performing analog-to-digital conversion on the received signal to obtain a digital state signal and transmitting the digital state signal to the signal isolation circuit;

the signal isolation circuit is used for isolating a power supply and the ground used by the earthquake ground resistivity detected signal and the digital state signal in the earthquake ground resistivity acquisition module and sending the digital state signal to the main control circuit;

the communication circuit is used for connecting with an upper computer and transmitting the digital state signal to the upper computer for data processing;

and the master control circuit is used for controlling the analog-to-digital conversion circuit to start and stop acquiring data signals and controlling the communication circuit to transmit the digital state signals to the upper computer.

And the alarm circuit is used for triggering an alarm prompt to be fed back to the main control circuit when the earthquake ground resistivity acquisition module fails.

According to another aspect of the present disclosure, a seismic ground resistivity acquisition device is provided, which includes a signal conditioning circuit, an analog-to-digital conversion circuit, a signal isolation circuit, a main control circuit, and a communication circuit; the signal conditioning circuit is connected with the analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is connected with the signal isolation circuit; the signal isolation circuit is connected with the main control circuit and the communication circuit; the earthquake ground resistivity acquisition device also comprises an alarm circuit, and the alarm circuit is connected with the main control circuit;

wherein the content of the first and second substances,

a signal conditioning module: the signal conditioning circuit is used for receiving the earthquake ground resistivity measured signal, performing impedance transformation and signal amplitude limiting on the received earthquake ground resistivity measured signal, and then transmitting a signal obtained through the impedance transformation and the signal amplitude limiting to the analog-to-digital converter;

an analog-to-digital conversion module: the analog-to-digital conversion circuit is used for performing analog-to-digital conversion on the received signal to obtain a digital state signal and transmitting the digital state signal to the signal isolation circuit;

the signal isolation module: the signal isolation circuit is used for isolating a power supply and the ground used by the earthquake ground resistivity detected signal and the digital state signal in the earthquake ground resistivity acquisition module and sending the digital state signal to the main control circuit;

the digital state signal transmission module: the communication circuit is used for connecting with an upper computer and transmitting the digital state signal to the upper computer for data processing;

a circuit control module: and the master control circuit is used for controlling the communication circuit to transmit the digital state signal to the upper computer.

The circuit alarm module: and the alarm circuit is used for triggering an alarm prompt to be fed back to the main control circuit when the earthquake ground resistivity acquisition module fails.

According to another aspect of the present disclosure, a seismic ground resistivity collecting system is provided, wherein the seismic ground resistivity collecting device is provided on the seismic ground resistivity collecting system.

This technical scheme that adopts of this disclosure possesses following beneficial effect at least:

the embodiment of the invention adopts the single chip STM32F103RBT6 with high module integration, simplifies the design of peripheral circuits, reduces the volume of an acquisition module, and improves the data processing speed of the 32-bit single chip; an advanced analog-to-digital converter is adopted, the input voltage range of the whole acquisition module reaches +/-2.5 v, and the number of measurement channels reaches 4; the signal conditioning circuit adopts a voltage stabilizing tube to carry out amplitude limiting, so that an input signal is prevented from exceeding the acquisition range of the analog-to-digital converter; the anti-interference capability is enhanced, and the interference of external interference on the earthquake ground resistivity acquisition module is reduced.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic diagram of a measurement of a seismic ground resistivity module of an embodiment of the disclosure;

FIG. 2 is a schematic diagram of current distribution of two opposite-point current sources at the earth's surface according to an embodiment of the disclosure;

FIG. 3 is a diagram of a circuit connection mode in a construction method of a seismic ground resistivity acquisition module according to an embodiment of the disclosure;

FIG. 4 is a circuit diagram of signal conditioning in a method for constructing a seismic ground resistivity acquisition module according to an embodiment of the disclosure;

FIG. 5 is an analog-to-digital conversion circuit diagram in a construction method of a seismic ground resistivity acquisition module according to an embodiment of the disclosure;

FIG. 6 is a circuit diagram of signal isolation in a construction method of a seismic ground resistivity acquisition module according to an embodiment of the disclosure;

FIG. 7 is a main control circuit diagram in a construction method of a seismic ground resistivity acquisition module according to an embodiment of the disclosure;

FIG. 8 is a circuit diagram of a power input indication in a construction method of a seismic ground resistivity acquisition module according to an embodiment of the disclosure;

FIG. 9 is a diagram of an alarm circuit in a method for constructing a seismic ground resistivity acquisition module according to an embodiment of the disclosure;

FIG. 10 is a communication circuit diagram in a construction method of a seismic ground resistivity acquisition module according to an embodiment of the disclosure;

FIG. 11 is a circuit diagram of other anti-interference designs in the construction method of the seismic ground resistivity acquisition module according to the embodiment of the disclosure;

FIG. 12 is a schematic diagram of an apparatus for seismic ground resistivity acquisition of an embodiment of the disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the technical solutions of the present application will be described in detail below. It is to be understood that the embodiments described are only a few embodiments of the present application and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without making any creative effort, shall fall within the protection scope of the present application.

The terms "first," "second," "third," "fourth," and the like in this disclosure are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. Furthermore, the terms "comprises" and "comprising," as well as any variations thereof, are intended to cover a non-exclusive inclusion, such as a list of steps or elements. A method, system, article, or apparatus is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, system, article, or apparatus.

As shown in fig. 1, a, B, M, N are four electrodes buried on the earth surface or inside, wherein a, B are power supply electrodes connected to a power supply; m and N are testing electrodes and are connected with a ground resistance observation instrument. In the case of wireless size, uniformity, level and isotropy of the underground medium, when the earth resistivity is measured, the current I is supplied to the underground medium through the power supply electrodes A and B, the current flows in from the electrode A and flows out from the electrode B, and the electrodes A and B can be regarded as two point power supplies with different polarities on the earth surface, as shown in FIG. 2.

The potential difference generated between the M electrode and the N electrode is delta U _MN ：

In the formula (1), AM, BM, AN, and BN are distances between electrodes a and M, B and M, a and N, and B and N, respectively, and the arrangement of four electrodes a, B, M, and N is referred to as AN observation device. ρ is the earth resistivity of the underground medium.

Earth resistivity ρ of underground medium:

in the formula (2), K is a constant, i.e., a device coefficient.

The current I can be obtained by a sampling resistor R connected in the loop in series _i The upper voltage, and therefore the ground resistivity measured by the ground resistivity observing means is of the formula (3)

The earthquake ground resistance acquisition module is mainly responsible for measuring voltage signals. In order to improve the precision, in recent years, each large station develops an underground earth resistivity observation method so as to reduce the influence of earth surface interference factors, but an acquisition module is required to be added with channels to meet the measurement requirements of horizontal and vertical directions, and the acquisition module is required to meet the following conditions for measuring high-precision signals:

the measuring electrode with high input impedance and ground resistivity is directly buried in the soil, and the ground resistance of the measuring electrode changes along with the change of external conditions, so that the voltage measuring input is required to have high impedance in order to improve the observation progress.

The ground resistivity measured signal is sent to the measuring instrument through a long lead, and the measuring instrument is communicated with the ground in a certain mode, so that the measured signal has other interference, such as 50Hz power frequency interference of commercial power, besides a direct current component, the interference is doped in the measured signal to greatly influence the measurement result, and the acquisition module is required to have strong anti-interference capability.

The existing earthquake ground resistivity acquisition module is developed in the middle and later periods of the eighties of the last century, and although the acquisition index of the existing earthquake ground resistivity acquisition module meets the observation requirement, the existing earthquake ground resistivity acquisition module is not suitable for some times along with the development of the observation technology.

The analog-digital conversion circuit of the earth resistivity acquisition module at the present stage adopts an AD7710 analog-digital converter as a chip, the converter is 24 bits, the maximum acquisition voltage is +/-1.2V after passing through the signal conditioning circuit, two differential channels are provided, expansion is carried out by controlling the selection of the relay, so that the number of the measurement channels is 3, and the quantity of the channels is insufficient for the current underground earth resistivity measurement; meanwhile, a singlechip chip adopted by the master control circuit of the existing ground resistivity acquisition module is 80C31, the singlechip only has 8-bit data processing width, does not have an on-chip program memory, and needs to be expanded by an external module, so that the whole circuit is complex in design and large in size; in addition, the signal isolation circuit of the existing ground resistivity acquisition module adopts a plurality of photoelectric coupling tubes for isolation, and the occupied circuit volume is large. And the phenomenon of difficult equipment maintenance exists at the present stage, although the components adopted by the existing earthquake ground resistivity acquisition module are in an advanced level when being designed, some of the products are stopped at present, so that the operation and maintenance of the existing earthquake ground resistivity acquisition module are difficult.

To above-mentioned problem, this disclosure chooses for use comparatively advanced collection components and parts ADS1256 to design novel earthquake ground resistivity collection module for voltage measurement scope reaches 2.5V, and the measuring channel reaches 4. And because many modules have been integrated to the master control circuit singlechip chip STM32F103RBT6 of choosing, abundant resources do not need too much peripheral circuit, make the design of whole circuit simplify a lot, in addition, other part circuits have also adopted the function comprehensive, the component that the volume is small is designed, make the whole volume of the earth quake resistivity collection module of this disclosure also compare and be less than 8 master control singlechip chips that used before, simultaneously singlechip chip STM32F103RBT6 is 32 bits singlechip, also compare and promote greatly before in the aspect of data processing speed.

In addition, voltage acquisition modules are designed by using a single chip microcomputer chip STM32F103RBT6 and an analog-to-digital converter ADS1256 on the market at present, but the voltage acquisition modules are not applied to the ground resistivity acquisition modules, and the ground resistivity observation has high requirements on the accuracy and the anti-interference capability of the acquisition modules, so that the single chip microcomputer chip STM32F103RBT6 and the analog-to-digital converter ADS1256 are selected for designing the ground resistivity acquisition modules. A signal conditioning circuit is added at a signal input end, a signal isolation circuit is added in the circuit, and the high precision and the high anti-interference capability are emphasized in circuit design and device selection so as to adapt to the earth resistivity observation requirement.

The connection mode of the earthquake ground resistivity module circuit of the embodiment of the disclosure is shown in fig. 3, wherein;

the signal conditioning circuit is used for receiving the earthquake ground resistivity measured signal, performing impedance transformation and signal amplitude limiting on the received earthquake ground resistivity measured signal, and transmitting a signal obtained through the impedance transformation and the signal amplitude limiting to the analog-to-digital converter;

the terminal P1_ IN is an input end of a signal to be tested for the earthquake ground resistivity, and each two paths of external voltage signals IN0, IN1, IN2, IN3, IN4, IN5, IN6 and IN7 form a differential signal which is divided into four channels and enters a signal conditioning circuit. Because the acquired voltage is direct-current voltage and can accompany with mixed high-frequency interference, the first low-pass filtering structure and the second low-pass filtering structure are adopted to filter high-frequency noise in the signal. The operational amplifier TLC2652 is adopted in the signal conditioning circuit, compared with other operational amplifiers, the noise and zero deviation of the operational amplifier TLC2652 are smaller, and the interference of the selected operational amplifier TLC2652 on the collected signals is smaller because the detected signals are weaker. Meanwhile, the operational amplifier TLC2652 is a chopper amplifier and can also inhibit the power frequency interference of 50Hz of the commercial power.

In terms of circuit connection, as shown in fig. 4, first, the forward output pin 5 of the operational amplifier TLC2652 is connected to the reverse input pin 4, and the forward input pin 5 is connected to the seismic earth resistivity detected signal passing through the first low-pass filtering structure. The connection method forms the connection method of the voltage follower, and achieves the effect that the amplification factor is 1, and the input signal is equal to the output signal. Meanwhile, the signal conditioning circuit is required to have high impedance to input signals and low impedance to a post-stage analog-to-digital converter, and the connection method of the voltage follower can also meet the requirements of large input impedance and small output impedance and impedance conversion.

And then a first pin 9 of the operational amplifier is connected to the reverse input pin 4, the earthquake ground resistivity measured signal passes through a forward output pin 10 and then is transmitted to a voltage stabilizing diode through a second low-pass filtering structure to carry out amplitude limiting on the earthquake ground resistivity measured signal, and finally, the difference flows into an analog-to-digital conversion circuit. The stabilizing diode will clip the signal input to the subsequent analog-to-digital conversion circuit, limiting the signal to within 3V.

The analog-to-digital conversion circuit converts the analog state signal into a digital state signal and transmits the digital state signal to the signal isolation circuit, as shown in fig. 5, wherein;

the reference voltage is provided at pin 2 input using chips including but not limited to ADR4525, ADR03-2.5, REF2925 model, and at pin 4 output 2.5V from pin 6 to analog-to-digital converter ADS1256, but is more accurate than the other ones produced by the ADR4525 chip. Meanwhile, peripheral capacitors of the ADR4525 filter power supply ripples to enable the seismic ground resistivity measured signal to be more accurate. And then signals subjected to amplitude limiting by the signal conditioning circuit are differentially input into an analog-to-digital converter ADS1256 for collection through AIN0 and AIN1, AIN2 and AIN3, AIN4 and AIN5, AIN6 and AIN7, so that the conversion from three channels to four channels in the prior art is realized, and the data processing speed is improved. Meanwhile, in the process of programming, the amplification factor of the ADS1256 is set to be 2, so that the acquisition range reaches +/-2.5V; the input mode is a differential input mode, so that common-mode interference can be reduced; the switching rate is set to be 10Hz, so that the notch point is positioned at 50Hz, and the interference of power frequency can be further inhibited.

The signal isolation circuit is used for isolating a power supply and the ground used by the seismic ground resistivity detected signal and the digital state signal in the seismic ground resistivity acquisition module, and sending the digital state signal to the main control circuit, as shown in fig. 6, wherein;

the signal conditioning circuit and the analog-to-digital conversion circuit use power supply and ground which are analog signals; the main control circuit, the alarm circuit and the communication circuit after passing through the analog-to-digital conversion circuit all use digital power and digital ground. The digital signal works in a pulse state, and the change speed is high, so that the noise on the digital ground is high; the analog signal is easily interfered by the outside and is also easily interfered; interference is introduced if the digital signal and the analog signal are mixed. In order to avoid interference, the anti-interference capability of the ground resistivity acquisition module is improved, and a signal isolation circuit is added. The photoelectric isolator is used for isolating the analog power supply and the analog ground from the digital power supply and the digital ground. The photoelectric isolator has the advantages of strong anti-interference capability, stable work, long service life and high transmission efficiency, and can meet the requirement of ground resistivity measurement. Meanwhile, communication signals between the analog converter ADS1256 and the main control STM32F103RBT6 are isolated in the signal isolation circuit.

The master control circuit controls the analog-to-digital conversion circuit to start and stop acquiring data signals, and controls a digital state signal obtained by the analog-to-digital conversion circuit to go to a machine position through the communication circuit, wherein the master control circuit is shown in fig. 7, and the communication circuit is shown in fig. 10;

the main control circuit single chip microcomputer chip adopts STM32F103RBT6, compared with the prior art, the design of a peripheral circuit is simplified, and the volume of an acquisition module is reduced; meanwhile, the STM32F103RBT6 type single chip microcomputer belongs to a 32-bit single chip microcomputer chip, and the data processing speed is improved compared with the prior art.

And secondly, the communication circuit sends the acquired voltage to an upper computer through an RS2323 serial port for data processing to obtain the ground resistivity.

The disclosed embodiment also includes a power input indication, as shown in fig. 8, where;

the power input indication is composed of a light emitting diode, an external power supply, an analog power supply, a digital power supply, an analog ground and a digital ground, when the corresponding power supply has voltage input, the corresponding light emitting diode is lightened, and whether the voltage passes through is judged.

The disclosed embodiment further comprises an alarm circuit comprising a buzzer and a triode, as shown in fig. 9, wherein;

when the program is halted and the circuit is abnormal, the alarm circuit sends a command to enable the base of the triode to be at a high level, so that the triode is in saturated conduction, and the buzzer gives out a sound alarm to prompt, so that maintenance personnel can maintain and ensure the normal work of the earthquake ground resistivity acquisition module in time.

Embodiments of the present disclosure also include other interference resistant designs, as shown in fig. 11, wherein;

in addition to the isolation term in the signal isolation circuit, it is also necessary to connect the analog ground and the digital ground in the whole circuit together into the ground. Wherein analog ground and digital ground are isolated by an OR resistor; the analog power supply and the digital power supply are isolated by the magnetic beads to reduce interference. Meanwhile, in order to reduce common mode interference caused by digital ground and analog ground, related devices of the digital ground and the analog ground need to be placed in a subarea mode during circuit board design, and copper is paved in the subarea mode to reduce mutual influence between the analog ground and the digital ground.

According to another aspect of the embodiments of the present disclosure, there is provided a seismic ground resistivity collecting apparatus, as shown in fig. 12, including:

the signal conditioning module 1201: the signal conditioning circuit is used for receiving the earthquake ground resistivity measured signal, performing impedance transformation and signal amplitude limiting on the received earthquake ground resistivity measured signal, and then transmitting a signal obtained through the impedance transformation and the signal amplitude limiting to the analog-to-digital converter;

analog-to-digital conversion module 1202: the analog-to-digital conversion circuit is used for performing analog-to-digital conversion on the received signal to obtain a digital state signal and transmitting the digital state signal to the signal isolation circuit;

the signal isolation module 1203: the signal isolation circuit is used for isolating a power supply and the ground used by the earthquake ground resistivity detected signal and the digital state signal in the earthquake ground resistivity acquisition module and sending the digital state signal to the main control circuit;

the digital state signal transmission module 1204: the communication circuit is used for connecting with the upper computer and transmitting the digital state signal to the upper computer for data processing;

the circuit control module 1205: and the master control circuit is used for controlling the analog-to-digital conversion circuit to start collecting and stop collecting data signals and controlling the communication circuit to transmit the digital state signals to the upper computer.

The circuit alarm module 1206: and the alarm circuit is used for triggering an alarm prompt to be fed back to the main control circuit when the earthquake ground resistivity acquisition module fails.

According to another aspect of the embodiments of the present disclosure, a seismic ground resistivity collecting system is provided, wherein the seismic ground resistivity collecting device is provided thereon.

It should be understood that various forms of the flows shown above may be used, with steps reordered, added, or deleted. For example, the steps described in this disclosure may be performed in parallel or sequentially or in a different order, and are not limited herein as long as the desired results of the disclosed embodiments are achieved.

The above detailed description should not be construed as limiting the scope of the disclosure. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may be made, depending on design requirements and other factors. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present disclosure should be included in the scope of protection of the present disclosure.

Claims (11)

1. A construction method of a seismic ground resistivity acquisition module is characterized in that the seismic ground resistivity acquisition module comprises a signal conditioning circuit, an analog-to-digital conversion circuit, a signal isolation circuit, a main control circuit and a communication circuit; the signal conditioning circuit is connected with the analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is connected with the signal isolation circuit; the signal isolation circuit is connected with the main control circuit and the communication circuit, wherein,

the signal conditioning circuit is used for receiving the earthquake ground resistivity measured signal, performing impedance transformation and signal amplitude limiting on the received earthquake ground resistivity measured signal, and then transmitting a signal obtained through the impedance transformation and the signal amplitude limiting to the analog-to-digital converter;

the analog-to-digital conversion circuit is used for performing analog-to-digital conversion on the received signal to obtain a digital state signal and transmitting the digital state signal to the signal isolation circuit;

the signal isolation circuit is used for isolating a power supply and the ground used by the seismic ground resistivity detected signal and the digital state signal in the seismic ground resistivity acquisition module and sending the digital state signal to the main control circuit;

the communication circuit is used for being connected with an upper computer and transmitting the digital state signal to the upper computer for data processing;

the master control circuit is used for controlling the analog-to-digital conversion circuit to start collecting and stop collecting signal data, and controlling the communication circuit to transmit the digital state signal to the upper computer.

2. The method for constructing a seismic ground resistivity acquisition module according to claim 1, further comprising an alarm circuit connected to the master control circuit;

and the alarm circuit is used for triggering an alarm prompt to be fed back to the main control circuit when the earthquake ground resistivity acquisition module fails.

3. The method of any of claims 1-2, the signal conditioning circuit comprising a first low pass filtering structure, an operational amplifier, a second low pass filtering structure, and a zener diode, wherein;

a forward output pin of the operational amplifier is connected to a reverse input pin of the operational amplifier, and the seismic ground resistivity measured signal is connected to the operational amplifier through the forward input pin by the first low-pass filtering structure;

the first pin of the operational amplifier is connected to the reverse input pin, the earthquake ground resistivity measured signal is output through the forward output pin and then transmitted to the voltage stabilizing diode through the second low-pass filtering structure to limit the amplitude of the earthquake ground resistivity measured signal, and finally the difference flows into the analog-to-digital conversion circuit.

4. The method of any one of claims 1-2, wherein the analog-to-digital conversion circuit comprises a reference voltage input and the analog-to-digital converter, the reference voltage input being connected to the analog-to-digital converter;

the reference voltage input device is used for providing reference voltage for the analog-to-digital converter;

the amplification factor G =2 of the analog-to-digital converter, the input mode is a differential input mode, and the conversion rate is set to 10Hz.

5. The method of any of claims 1-2, the signal isolation circuitry comprising a photo-isolator, an analog power supply, an analog ground, a digital power supply, and a digital ground, wherein,

the photoelectric isolator isolates the analog power supply and the analog ground from the digital power supply and the digital ground, and transmits the acquisition result of the analog-to-digital conversion circuit to a main control circuit.

6. The method of claim 3, wherein the operational amplifier is of chip type TLC2652.

7. The method of claim 4, wherein the chip model of the analog-to-digital converter is ADS1256.

8. The method according to any one of claims 1-2, wherein the type of a single chip used by the main control circuit is STM32F103RBT6.

9. The earthquake ground resistivity acquisition device is characterized in that the earthquake ground resistivity acquisition module comprises a signal conditioning circuit, an analog-to-digital conversion circuit, a signal isolation circuit, a main control circuit and a communication circuit; the signal conditioning circuit is connected with the analog-to-digital conversion circuit, and the analog-to-digital conversion circuit is connected with the signal isolation circuit; the signal isolation circuit is connected with the main control circuit and the communication circuit, wherein the signal isolation circuit is connected with the main control circuit and the communication circuit;

a signal conditioning module: the signal conditioning circuit is used for receiving the earthquake ground resistivity measured signal, performing impedance transformation and signal amplitude limiting on the received earthquake ground resistivity measured signal, and then transmitting a signal obtained through the impedance transformation and the signal amplitude limiting to the analog-to-digital converter;

an analog-to-digital conversion module: the analog-to-digital conversion circuit is used for performing analog-to-digital conversion on the received signal to obtain a digital state signal and transmitting the digital state signal to the signal isolation circuit;

the signal isolation module: the signal isolation circuit is used for isolating a power supply and the ground used by the seismic ground resistivity detected signal and the digital state signal in the seismic ground resistivity acquisition module and sending the digital state signal to the main control circuit;

the digital state signal transmission module: the communication circuit is used for connecting with an upper computer and transmitting the digital state signal to the upper computer for data processing;

a circuit control module: the master control circuit is used for controlling the analog-to-digital conversion circuit to start collecting and stop collecting signal data, and controlling the communication circuit to transmit the digital state signal to the upper computer.

10. The seismic ground resistivity acquisition device of claim 9 further comprising an alarm circuit, the alarm circuit connected to the master control circuit;

the circuit alarm module: and the alarm circuit is used for triggering an alarm prompt to be fed back to the main control circuit when the earthquake ground resistivity acquisition module fails.

11. A seismic ground resistivity collecting system, characterized in that the seismic ground resistivity collecting system is provided with a seismic ground resistivity collecting device according to any one of claims 9 to 10.

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