Non-contact measurement and calculation method and system for ultra-low resistivity

Abstract

The present invention discloses a non-contact measurement and calculation method for ultra-low resistivity, including determining a test material of known resistivity; using the test material to prepare a test specimen of standard specification and shape; measuring and recording the environmental and measuring instrument noise under the condition that the environmental electromagnetic interference is less than a set threshold; measuring the eddy current secondary vertical magnetic field response of the prepared test specimen; selecting a signal window; calculating the area value of the eddy current secondary vertical magnetic field response curve of the test specimen within the signal window; fitting the mathematical expression between the area value and the resistivity of the test material and obtaining a resistivity calculation formula; using the resistivity calculation formula to directly calculate the resistivity of the target material to be tested, and completing the non-contact measurement and calculation of ultra-low resistivity. The present invention also discloses a system for realizing the non-contact measurement and calculation method for ultra-low resistivity. The present invention overcomes the shortcomings of conventional specimen resistivity due to contact measurement, and has higher reliability and better accuracy.

Description

Technical Field

[0001] The invention belongs to the field of geological exploration, and in particular relates to a non-contact measurement and calculation method and system for ultra-low resistivity. Background Art

[0002] Opposing-coils transient electromagnetic method (OCTEM) uses an inductive excitation method, where an ungrounded loop is used to emit a primary changing electromagnetic field into the ground, and a receiving coil receives the changing secondary electromagnetic field generated by underground eddy currents. This method uses two upper and lower parallel coaxial coils of the same size, and currents of equal magnitude and opposite directions are passed through them as the transmitting source, and the underground secondary field is received on the plane of zero magnetic flux of the primary field synthesized by the double coil source, and the pure secondary field coupled to the center of the ground is measured. Since the receiving coil is in the equivalent anti-flux plane of the double transmitting coil, its primary field magnetic flux is always zero. When the transmitting current is turned off, the magnetic flux generated by the upper and lower coils cancel each other, and the primary field magnetic flux of the receiving coil is zero, which is equivalent to eliminating the blind spot of the conventional transient electromagnetic method, and can receive the decay law of the early secondary field over time, and obtain the geoelectric information of the shallow underground medium. Different from the conventional transient electromagnetic method which often uses a single coil for transmission and a single coil for reception, the equivalent reverse flux transient electromagnetic method uses dual coils for transmission and a single coil for reception and has a certain spatial structure, eliminating the mutual inductance effect between the transmitting and receiving coils. This is a new transient electromagnetic detection method for measuring pure secondary electromagnetic fields coupled in the ground, and can also be used to measure the transient electromagnetic response of ultra-low resistivity specimens.

[0003] There are many methods for measuring the resistivity of a specimen, which can be divided into contact measurement and non-contact measurement based on whether the measuring electrode is in contact with the specimen. Among them, the contact measurement methods include the bridge method, voltammetry, dipole method, quadrupole method, four-probe method, etc.; while the non-contact measurement methods include eddy current method, plasma resonance infrared method and microwave scanning microscope probe test method.

[0004] However, both the contact measurement method and the non-contact measurement method have the problems of low measurement accuracy and poor measurement reliability when measuring the resistivity of ultra-low resistivity samples. Summary of the invention

[0005] One of the purposes of the present invention is to provide a non-contact measurement and calculation method of ultra-low resistivity with high reliability and good accuracy.

[0006] A second object of the present invention is to provide a system for implementing the non-contact measurement and calculation method of ultra-low resistivity.

[0007] The non-contact measurement and calculation method of ultra-low resistivity provided by the present invention comprises the following steps:

[0008] S1. Determine the test material of known resistivity;

[0009] S2. Prepare test specimens of standard specifications and shapes using test materials;

[0010] S3. Under the condition that the environmental electromagnetic interference is less than the set threshold, measure and record the environmental and measuring instrument noise;

[0011] S4. Measuring the eddy current secondary perpendicular magnetic field response of the test specimen prepared in step S2;

[0012] S5. Select the signal window;

[0013] S6. Using a mathematical integral summation method, calculate the area value of the eddy current secondary perpendicular magnetic field response curve of the test specimen obtained in step S4 within the signal window selected in step S5;

[0014] S7. Using a mathematical fitting method, the mathematical expression between the area value and the resistivity of the test material obtained in step S6 is fitted to obtain a resistivity calculation formula;

[0015] S8. Use the resistivity calculation formula obtained in step S7 to directly calculate the resistivity of the target material to be tested, and complete the non-contact measurement calculation of ultra-low resistivity.

[0016] Determining the test material of known resistivity in step S1 specifically includes the following steps:

[0017] Test materials of known resistivity that were determined included aluminum, iron, and copper.

[0018] The step S2 of using the test material to prepare a test specimen of standard specifications and shape specifically includes the following steps:

[0019] A test specimen of a standard shape is prepared using the test material; the standard shape is a cuboid of 30×30×15 mm.

[0020] The step S3, under the condition that the environmental electromagnetic interference is less than the set threshold, measures and records the environmental and measuring instrument noise, specifically comprises the following steps:

[0021] Under the condition that the environmental electromagnetic interference is less than the set threshold, a transient electromagnetic system is used to measure and record the environmental and measuring instrument noise.

[0022] The step S4 of measuring the eddy current secondary perpendicular magnetic field response of the test specimen prepared in the step S2 specifically includes the following steps:

[0023] Using a transient electromagnetic system, measuring the eddy current secondary perpendicular magnetic field response of the test specimen prepared in step S2;

[0024] During measurement, the antenna is placed horizontally on the specimen; the distance between the antenna and the mainframe of the transient electromagnetic system is greater than 4m and as far as possible; the distance between the antenna and the operating computer of the transient electromagnetic system is greater than 5m; the distance between the operating computer and the mainframe in a horizontal line of sight state does not exceed 30m; at the test site, the test personnel and other animals are as far away from the antenna as possible, and the transmission cable of the transient electromagnetic system is not entangled or coiled;

[0025] The environmental and measuring instrument noises measured in step S3 are subtracted from the measured data, and data fitting is performed to obtain an eddy current secondary perpendicular magnetic field response curve of the test specimen;

[0026] The selected signal window described in step S5 specifically includes the following steps:

[0027] In the eddy current secondary vertical magnetic field response curve of the test specimen, the signal window is the first ray and the second ray located in the first quadrant of the coordinate axis with the origin as the endpoint; among them, the angle between the first ray and the positive direction of the X-axis is 30°, and the angle between the second ray and the positive direction of the X-axis is 75°.

[0028] The method of using mathematical integral summation to calculate the area value of the eddy current secondary vertical magnetic field response curve of the test specimen obtained in step S4 within the signal window selected in step S5 in step S6 specifically includes the following steps:

[0029] The area enclosed by the eddy current secondary perpendicular magnetic field response curve of the test specimen obtained in step S4 and the signal window selected in step S5 is the area to be calculated;

[0030] The area value S to be calculated is calculated using the following formula:

[0031]

[0032] Where X 1 is the horizontal coordinate value of the intersection of the first ray and the eddy current secondary vertical magnetic field response curve of the test specimen; 2 is the horizontal coordinate value of the intersection of the second ray and the eddy current secondary perpendicular magnetic field response curve of the test specimen; f(x) is the function expression of the eddy current secondary perpendicular magnetic field response curve of the test specimen.

[0033] The mathematical fitting method described in step S7 is used to fit the mathematical expression between the area value obtained in step S6 and the resistivity of the test material to obtain a resistivity calculation formula, which specifically includes the following steps:

[0034] Using a mathematical fitting method, taking a Gaussian function as a basis function, the fitting step S6 obtains a mathematical expression between the area value and the resistivity of the test material;

[0035] Finally, the following resistivity calculation formula is obtained by fitting:

[0036]

[0037] Where f ρ is the resistivity calculated by fitting.

[0038] The resistivity calculation formula obtained in step S7 is used in step S8 to directly calculate the resistivity of the target material to be tested, which specifically includes the following steps:

[0039] Determine the target material to be tested;

[0040] Using the target material to be tested as the test material;

[0041] Steps S2 to S6 are used to calculate and obtain the area value of the target material to be tested;

[0042] According to the obtained area value, the resistivity calculation formula obtained in step S7 is used to calculate the resistivity of the target material to be tested.

[0043] The present invention also provides a system for realizing the contactless measurement and calculation method of ultra-low resistivity, comprising a material determination module, a specimen preparation module, a noise measurement module, a response measurement module, a window selection module, an area calculation module, a resistivity fitting module and a resistivity calculation module; the material determination module, the specimen preparation module, the noise measurement module, the response measurement module, the window selection module, the area calculation module, the resistivity fitting module and the resistivity calculation module are sequentially connected in series; the material determination module is used to determine the test material of known resistivity, and upload the data information to the specimen preparation module; the specimen preparation module is used to prepare a test specimen of a standard specification shape using the test material according to the received data information, and upload the data information to the noise measurement module; the noise measurement module is used to measure and record the environment and measurement instrument noise according to the received data information, under the condition that the environmental electromagnetic interference is less than a set threshold, and upload the data information to the response measurement module; the response measurement module It is used to measure the eddy current secondary perpendicular magnetic field response of the prepared test specimen according to the received data information, and upload the data information to the window selection module; the window selection module is used to select the signal window according to the received data information, and upload the data information to the area calculation module; the area calculation module is used to calculate the area value of the eddy current secondary perpendicular magnetic field response curve of the test specimen in the selected signal window according to the received data information, using the mathematical integral summation method, and upload the data information to the resistivity fitting module; the resistivity fitting module is used to fit the mathematical expression between the area value and the resistivity of the test material according to the received data information, using the mathematical fitting method, to obtain the resistivity calculation formula, and upload the data information to the resistivity calculation module; the resistivity calculation module is used to directly calculate the resistivity of the target material to be tested according to the received data information using the obtained resistivity calculation formula, and complete the non-contact measurement calculation of ultra-low resistivity.

[0044] The non-contact measurement and calculation method and system of ultra-low resistivity provided by the present invention are based on the equivalent reverse flux transient electromagnetic method, and use mathematical methods to obtain an approximate function between the specimen area and the specimen resistivity, and calculate the resistivity of the material according to the function; therefore, the present invention can not only realize the non-contact measurement and calculation of ultra-low resistivity, but also overcome the shortcomings of conventional specimen resistivity due to contact measurement, and has higher reliability and better accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The figure is a schematic diagram of the method flow of the present invention.

[0046] Figure 2 A schematic diagram of the environmental noise collected by the transient electromagnetic system in the method of the present invention.

[0047] Figure 3Schematic diagram of data collection for copper specimens in the method of the present invention.

[0048] Figure 4 Schematic diagram of data collection for iron samples in the method of the present invention.

[0049] Figure 5 Schematic diagram of data collection for aluminum specimens in the method of the present invention.

[0050] Figure 6 It is a curve schematic diagram of the response curve and signal window of the copper specimen in the method of the present invention.

[0051] Figure 7 It is a curve schematic diagram of the response curve and signal window of the iron sample in the method of the present invention.

[0052] Figure 8 It is a curve schematic diagram of the response curve and signal window of the aluminum specimen in the method of the present invention.

[0053] Fig. 9 It is a schematic diagram of the relationship between the fitting curve of area and resistivity in the method of the present invention.

[0054] Fig.10 This is a schematic diagram of data collection for the first alloy in an embodiment of the method of the present invention.

[0055] Fig.11 This is a schematic diagram of data collection for the second alloy in an embodiment of the method of the present invention.

[0056] Fig.12 Schematic diagram of the response curve of the first alloy and the area to be calculated in the embodiment of the method of the present invention.

[0057] Fig.13 Schematic diagram of the response curve of the second alloy and the area to be calculated in the embodiment of the method of the present invention.

[0058] Fig.14 It is a schematic diagram of the relationship between the resistivity of the first alloy measured by the prior art method in the embodiment of the method of the present invention and the approximate curve of the resistivity of the second alloy and the resistivity of the method of the present invention.

[0059] Fig.15 Schematic diagram of the functional modules of the system of the present invention. DETAILED DESCRIPTION

[0060] like Figure 1 The method flow chart of the method of the present invention is shown as follows: The non-contact measurement and calculation method of ultra-low resistivity disclosed in the present invention comprises the following steps:

[0061] S1. Determine the test material with known resistivity; specifically include the following steps:

[0062] The test materials with known resistivity include copper, iron and aluminum, and their corresponding resistivity at room temperature (20 degrees Celsius) is 1.7×10 -8 Ω·m, 10×10 -8 Ω·m and 2.82×10 -8 Ω·m;

[0063] S2. Prepare a test specimen of standard shape using the test material; specifically including the following steps:

[0064] A test specimen of standard shape is prepared using a test material; the standard shape is a cuboid of 30×30×15 mm;

[0065] S3. Under the condition that the environmental electromagnetic interference is less than the set threshold, measure and record the environmental and measuring instrument noise; specifically, the steps include:

[0066] Under the condition that the environmental electromagnetic interference is less than the set threshold, the transient electromagnetic system is used to measure and record the environmental and measuring instrument noise;

[0067] like Figure 2 The figure shows the environment and instrument noise collected by the high-precision transient electromagnetic system. It can be seen that the sending current is 3.3A, the shutdown time is 12.0μs, the collected noise data points are relatively scattered, and the response amplitude decreases with time.

[0068] S4. Measuring the eddy current secondary perpendicular magnetic field response of the test specimen prepared in step S2; specifically comprising the following steps:

[0069] Using a transient electromagnetic system, measuring the eddy current secondary perpendicular magnetic field response of the test specimen prepared in step S2;

[0070] During measurement, the antenna should be placed horizontally on the specimen to ensure the validity of the data; the distance between the antenna and the host of the transient electromagnetic system should be greater than 4m, and as far as possible while ensuring that the connecting line is long enough; the distance between the antenna and the operating computer of the transient electromagnetic system should be greater than 5m to avoid PC interference with the data; the distance between the operating computer and the host should not exceed 30m in a horizontal line of sight state; at the test site, the test personnel and other animals should be as far away from the antenna as possible, and the transmission cable of the transient electromagnetic system should not be entangled or circled;

[0071] The measured data is deducted from the environmental and measuring instrument noise measured in step S3, and data fitting (preferably cubic spline interpolation fitting) is performed to obtain the eddy current secondary perpendicular magnetic field response curve of the test specimen; Figure 3 The data collection diagram of copper (Cu) specimen is shown. Figure 4 This is the data collection diagram for the iron (Fe) sample. Figure 5This is the data collection diagram of aluminum (Al) specimen;

[0072] S5. Select the signal window; specifically includes the following steps:

[0073] In the eddy current secondary vertical magnetic field response curve of the test specimen, the signal window is the first ray and the second ray located in the first quadrant of the coordinate axis with the origin as the endpoint; wherein the angle between the first ray and the positive direction of the X-axis is 30°, and the angle between the second ray and the positive direction of the X-axis is 75°;

[0074] S6. Using a mathematical integral summation method, calculate the area value of the eddy current secondary vertical magnetic field response curve of the test specimen obtained in step S4 within the signal window selected in step S5; specifically comprising the following steps:

[0075] The area enclosed by the eddy current secondary perpendicular magnetic field response curve of the test specimen obtained in step S4 and the signal window selected in step S5 is the area to be calculated;

[0076] The area value S to be calculated is calculated using the following formula:

[0077]

[0078] Where X 1 is the horizontal coordinate value of the intersection of the first ray and the eddy current secondary vertical magnetic field response curve of the test specimen; 2 is the abscissa value of the intersection of the second ray and the eddy current secondary vertical magnetic field response curve of the test specimen; f(x) is the function expression of the eddy current secondary vertical magnetic field response curve of the test specimen;

[0079] Figure 6 The response curve of the copper (Cu) specimen and the schematic diagram of the area to be calculated are shown in Figure 2. Figure 7 The schematic diagram of the response curve of the iron (Fe) specimen and the area to be calculated is shown in Figure 2. Figure 8 It is a schematic diagram of the response curve of aluminum (Al) specimen and the area to be calculated;

[0080] S7. Using a mathematical fitting method, the fitting step S6 obtains a mathematical expression between the area value and the resistivity of the test material to obtain a resistivity calculation formula; specifically comprising the following steps:

[0081] Fig. 9 is a schematic diagram of an approximation curve of area and resistivity; a mathematical fitting method is adopted, and a Gaussian function is used as a basis function, and a fitting step S6 is performed to obtain a mathematical expression between the area value and the resistivity of the test material;

[0082] Finally, the following resistivity calculation formula is obtained by fitting:

[0083]

[0084] Where f ρ is the resistivity calculated by fitting;

[0085] S8. Using the resistivity calculation formula obtained in step S7, directly calculate the resistivity of the target material to be tested, and complete the non-contact measurement calculation of ultra-low resistivity; specifically comprising the following steps:

[0086] Determine the target material to be tested;

[0087] Using the target material to be tested as the test material;

[0088] Steps S2 to S6 are used to calculate and obtain the area value of the target material to be tested;

[0089] According to the obtained area value, the resistivity calculation formula obtained in step S7 is used to calculate the resistivity of the target material to be tested.

[0090] The effect of the method of the present invention is further described below in conjunction with an embodiment:

[0091] The existing first alloy and second alloy are randomly selected, and the resistivity of the first alloy is measured by the existing method to be 11.95×10 -8 Ω·m, the resistivity of the second alloy is 6.90×10 -8 Ω·m;

[0092] Then, the data collection diagram of the first alloy is measured by the method of the present invention as follows: Fig.10 As shown, the data acquisition diagram of the second alloy is as follows Fig.11 As shown;

[0093] Next, the response curve of the first alloy and the schematic diagram of the area to be calculated are measured using the method of the present invention. Fig.12 As shown, the response curve of the second alloy and the schematic diagram of the area to be calculated are shown in Fig.13 As shown;

[0094] Finally, the resistivity of the first alloy and the resistivity of the second alloy measured by the existing method are related to the approximate curve of the resistivity obtained by the method of the present invention as follows: Fig.14 shown; from Fig.14 It can be seen that the resistivity measured by the existing method is very consistent with the approximate curve of the resistivity of the method of the present invention, which shows that the method of the present invention has good reliability and accuracy.

[0095] Finally, through calculation, the SSE (sum of squared errors) index of the proposed method is 5.223×10 -6 , R 2 (Determination coefficient) index is 1, and the modified R 2The index is 1, and the RMSE (root mean square error) index is 0.001616; it can be seen that the method of the present invention does have good reliability and accuracy.

[0096] like Fig.15 The functional module schematic diagram of the system of the present invention is shown as follows: the system for realizing the non-contact measurement and calculation method of ultra-low resistivity disclosed in the present invention comprises a material determination module, a specimen preparation module, a noise measurement module, a response measurement module, a window selection module, an area calculation module, a resistivity fitting module and a resistivity calculation module; the material determination module, the specimen preparation module, the noise measurement module, the response measurement module, the window selection module, the area calculation module, the resistivity fitting module and the resistivity calculation module are connected in series in sequence; the material determination module is used to determine the test material of known resistivity and upload the data information to the specimen preparation module; the specimen preparation module is used to prepare a test specimen of standard specification shape using the test material according to the received data information, and upload the data information to the noise measurement module; the noise measurement module is used to measure and record the environment and measurement instrument noise according to the received data information under the condition that the environmental electromagnetic interference is less than the set threshold, and upload the data information to the response measurement module. block; the response measurement module is used to measure the eddy current secondary perpendicular magnetic field response of the prepared test specimen according to the received data information, and upload the data information to the window selection module; the window selection module is used to select the signal window according to the received data information, and upload the data information to the area calculation module; the area calculation module is used to calculate the area value of the eddy current secondary perpendicular magnetic field response curve of the test specimen in the selected signal window according to the received data information, using the mathematical integral summation method, and upload the data information to the resistivity fitting module; the resistivity fitting module is used to fit the mathematical expression between the area value and the resistivity of the test material according to the received data information, using the mathematical fitting method, to obtain the resistivity calculation formula, and upload the data information to the resistivity calculation module; the resistivity calculation module is used to directly calculate the resistivity of the target material to be tested according to the received data information and the obtained resistivity calculation formula, and complete the non-contact measurement calculation of ultra-low resistivity.

Claims

1. A non-contact measurement and calculation method for ultra-low resistivity, comprising the following steps: S1. Determine the test material of known resistivity; S2. Prepare test specimens of standard specifications and shapes using test materials; S3. Under the condition that the environmental electromagnetic interference is less than the set threshold, measure and record the environmental and measuring instrument noise; S4. Measuring the eddy current secondary perpendicular magnetic field response of the test specimen prepared in step S2; S5. Select the signal window; specifically, the steps include: In the eddy current secondary vertical magnetic field response curve of the test specimen, the first ray and the second ray with the origin as the endpoint and located in the first quadrant of the coordinate axis are selected as signal windows; wherein, The angle between the first ray and the positive direction of the X-axis is 30°, and the angle between the second ray and the positive direction of the X-axis is 75°; S6. Using a mathematical integral summation method, calculate the area value of the eddy current secondary perpendicular magnetic field response curve of the test specimen obtained in step S4 within the signal window selected in step S5; S7. Using a mathematical fitting method, a mathematical expression between the area value obtained in step S6 and the resistivity of the test material is fitted to obtain a resistivity calculation formula; S8. Use the resistivity calculation formula obtained in step S7 to directly calculate the resistivity of the target material to be tested, and complete the non-contact measurement calculation of ultra-low resistivity.

2. The non-contact measurement and calculation method of ultra-low resistivity according to claim 1 is characterized in that Determining the test material of known resistivity in step S1 specifically includes the following steps: Test materials of known resistivity that were determined included aluminum, iron, and copper.

3. The non-contact measurement and calculation method of ultra-low resistivity according to claim 2 is characterized in that The step S2 of using the test material to prepare a test specimen of standard specifications and shape specifically includes the following steps: A test specimen of a standard shape is prepared using the test material; the standard shape is a cuboid of 30×30×15 mm.

4. The non-contact measurement and calculation method of ultra-low resistivity according to claim 3 is characterized in that The step S3, under the condition that the environmental electromagnetic interference is less than the set threshold, measures and records the environmental and measuring instrument noise, specifically comprises the following steps: Under the condition that the environmental electromagnetic interference is less than the set threshold, a transient electromagnetic system is used to measure and record the environmental and measuring instrument noise.

5. The non-contact measurement and calculation method of ultra-low resistivity according to claim 4 is characterized in that The step S4 of measuring the eddy current secondary perpendicular magnetic field response of the test specimen prepared in the step S2 specifically includes the following steps: Using a transient electromagnetic system, measuring the eddy current secondary perpendicular magnetic field response of the test specimen prepared in step S2; During measurement, place the antenna horizontally on the specimen; the distance between the antenna and the host of the transient electromagnetic system is greater than 4m and as far as possible; the distance between the antenna and the operating computer of the transient electromagnetic system is greater than 5m; the distance between the operating computer and the host in a horizontal line of sight state is no more than 30m; At the test site, testers and other animals are as far away from the antenna as possible, and the transmission cable of the transient electromagnetic system is not tangled or coiled; The environmental and measuring instrument noises measured in step S3 are subtracted from the measured data, and data fitting is performed to obtain the eddy current secondary perpendicular magnetic field response curve of the test specimen.

6. The non-contact measurement and calculation method of ultra-low resistivity according to claim 5 is characterized in that The method of using mathematical integral summation to calculate the area value of the eddy current secondary vertical magnetic field response curve of the test specimen obtained in step S4 within the signal window selected in step S5 in step S6 specifically includes the following steps: The area enclosed by the eddy current secondary perpendicular magnetic field response curve of the test specimen obtained in step S4 and the signal window selected in step S5 is the area to be calculated; The area value S to be calculated is calculated using the following formula: Wherein X1 is the horizontal coordinate value of the intersection of the first ray and the eddy current secondary vertical magnetic field response curve of the test specimen; X2 is the horizontal coordinate value of the intersection of the second ray and the eddy current secondary vertical magnetic field response curve of the test specimen; f(x) is the function expression of the eddy current secondary vertical magnetic field response curve of the test specimen.

7. The non-contact measurement and calculation method of ultra-low resistivity according to claim 6 is characterized in that The mathematical fitting method described in step S7 is used to fit the mathematical expression between the area value obtained in step S6 and the resistivity of the test material to obtain a resistivity calculation formula, which specifically includes the following steps: Using a mathematical fitting method, taking a Gaussian function as a basis function, the fitting step S6 obtains a mathematical expression between the area value and the resistivity of the test material; Finally, the following resistivity calculation formula is obtained by fitting: Where f ρ is the resistivity calculated by fitting.

8. The non-contact measurement and calculation method of ultra-low resistivity according to claim 7, characterized in that The resistivity calculation formula obtained in step S7 is used in step S8 to directly calculate the resistivity of the target material to be tested, which specifically includes the following steps: Determine the target material to be tested; Using the target material to be tested as the test material; Steps S2 to S6 are used to calculate and obtain the area value of the target material to be tested; According to the obtained area value, the resistivity calculation formula obtained in step S7 is used to calculate the resistivity of the target material to be tested.

9. A system for realizing the non-contact measurement and calculation method of ultra-low resistivity according to any one of claims 1 to 8, characterized in that It includes a material determination module, a specimen preparation module, a noise measurement module, a response measurement module, a window selection module, an area calculation module, a resistivity fitting module and a resistivity calculation module; the material determination module, the specimen preparation module, the noise measurement module, the response measurement module, the window selection module, the area calculation module, the resistivity fitting module and the resistivity calculation module are connected in series in sequence; the material determination module is used to determine the test material with known resistivity, and upload the data information to the specimen preparation module; the specimen preparation module is used to prepare a test specimen of a standard specification shape using the test material according to the received data information, and upload the data information to the noise measurement module; the noise measurement module is used to measure and record the environment and measuring instrument noise according to the received data information, under the condition that the environmental electromagnetic interference is less than the set threshold, and upload the data information to the response measurement module; the response measurement module is used to measure the eddy current secondary perpendicular magnetic field response of the prepared test specimen according to the received data information, and upload the data information to the window selection module; The window selection module is used to select the signal window according to the received data information, and upload the data information to the area calculation module; The area calculation module is used to calculate the area value of the eddy current secondary perpendicular magnetic field response curve of the test specimen within the selected signal window according to the received data information by using the mathematical integral summation method, and upload the data information to the resistivity fitting module; the resistivity fitting module is used to fit the mathematical expression between the area value and the resistivity of the test material according to the received data information by using the mathematical fitting method, obtain the resistivity calculation formula, and upload the data information to the resistivity calculation module; the resistivity calculation module is used to directly calculate the resistivity of the target material to be tested according to the received data information by using the obtained resistivity calculation formula, and complete the non-contact measurement calculation of ultra-low resistivity.

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