Sputtering film multi-direction integrated eddy current sensor and signal conditioning method thereof

Abstract

The invention provides a sputtering film multi-direction integrated eddy current sensor and a signal conditioning method thereof. Comprising a sputtering film sensing probe and a conditioning circuit, and sensing wire grids are plated on five surfaces of the sensing probe respectively to realize distance sensing in five directions. The induction wire grid and the tap of the induction wire grid are introduced into the circuit, the induction wire grid and the resonant capacitor form an oscillating circuit, feedback voltage is formed at the tap, sine voltage of the feedback circuit is connected to an emitting electrode of the triode, direct-current detection can be carried out at a collector electrode of the triode, and the detected voltage can be used for amplification and zero setting. And finally, a standard voltage signal of 0.2 V to 4.8 V is output. According to the invention, wire grid signals of five sensing surfaces are conditioned, and five paths of standardized voltage signals can be output after conditioning; the sensor also has the characteristics of small volume and high temperature resistance, and can be applied to metal flaw detection or distance detection in a micro space and a high-temperature environment.

Description

Technical Field

[0001] The invention belongs to the field of testing and measurement, and in particular relates to an eddy current sensor and a signal conditioning method thereof. Background Art

[0002] Eddy current sensors are widely used in industrial production and in various measurement, detection, control and monitoring fields. For example, precision machinery, automobiles, aerospace, electronic equipment, chemicals, instrumentation, metrology, material testing, production process control and other fields. In these fields, eddy current sensors have the advantages of high-precision measurement, non-contact detection, high sensitivity, and high-speed response.

[0003] The eddy current sensor can measure the distance between the metal conductor being measured and the probe surface statically or dynamically, non-contact, highly linearly and with high resolution. It is a non-contact linear measurement tool that can accurately measure the static and dynamic relative displacement changes between the measured object and the probe end face.

[0004] However, in some special environments, such as high temperature environments and distance detection in small spaces, ordinary eddy current sensors cannot meet the use requirements. Moreover, with the development of science and technology, new industries and fields have also generated special needs. For example, in the fields of robotic arms, robot intelligent perception, intelligent obstacle avoidance, etc., multi-directional perception is required, and ordinary eddy current sensors can only detect in a single direction and cannot meet the requirements. Summary of the invention

[0005] In view of this, the present invention proposes a sputtered thin film multi-directional integrated eddy current sensor and a signal conditioning method thereof. The eddy current sensor consists of two parts: a sputtered thin film sensing probe and a conditioning circuit. Sensing wire grids are plated on the five surfaces of the sensing probe respectively, which can realize distance sensing in five directions. The sensor also has the characteristics of small size and high temperature resistance, and can be used for metal flaw detection or distance detection in small spaces and high temperature environments. The eddy current sensor can detect metal materials in multiple directions, and its signal conditioning method can be used for signal conditioning of this type or similar types of eddy current sensors. The present invention introduces the sensing wire grid and its tap into the circuit, and an oscillation circuit is formed by the sensing wire grid and the resonant capacitor, and a feedback voltage is formed at the tap. The sinusoidal voltage of the feedback circuit is connected to the emitter of the transistor, and DC detection can be performed at the collector of the transistor. The voltage after detection can be used for amplification and zeroing processing, and finally a standard voltage signal of 0.2V to 4.8V is output. The present invention can condition the wire grid signals of the five sensing surfaces in the above manner, and after conditioning, five standardized voltage signals can be output;

[0006] The specific technical solutions are as follows:

[0007] A sputtered thin film multi-directional integrated eddy current sensor comprises a sputtered thin film sensing probe and a conditioning circuit, wherein the sputtered thin film sensing probe is realized by plating a sensing wire grid on a ceramic material through the sputtered thin film technology, and the sensing wire grid is used to sense the distance to an external metal material; the conditioning circuit comprises a resonant capacitor, and the resonant capacitor and a single sensing wire grid are equivalent to an inductor L to form an LC resonant circuit; when resonating, the sensing wire grid emits an alternating electric field outward, and the alternating electric field will generate an alternating magnetic field in space; when metal approaches, the alternating magnetic field will generate eddy currents on the metal surface, and the eddy currents will generate a magnetic field in the opposite direction, affecting the electric field of the sensing wire grid, causing the electrical characteristics of the sensing wire grid to change, and the conditioning circuit detects the change to detect the distance between the sensing wire grid and the metal being measured.

[0008] Each sensing wire grid can be used to sense the distance between it and external metal materials.

[0009] Furthermore, the ceramic material is square, and an induction wire grid is plated on any one or more surfaces; the minimum width of the wire grid is micron level; and the ceramic matrix is ​​aluminum oxide or silicon nitride material.

[0010] Furthermore, a temperature compensating wire grid is plated at the same time as the induction wire grid is plated. The temperature compensating wire grid is used to compensate for the temperature drift of the induction wire grid. The plated induction wire grid and its temperature compensating wire grid are both made of high-temperature resistant metal materials; one end of the temperature compensating wire grid is connected to one end of the induction wire grid, and the other end of the temperature compensating wire grid is connected to the incoming line end pad, and the other end of the induction wire grid is connected to the return line end pad. The incoming line end pad and the return line end pad are used to supply power to the induction wire grid to form an electrical circuit, and then the tap end pad is led out from the induction wire grid for connecting to the oscillation and detection circuit to generate a feedback voltage.

[0011] Furthermore, the conditioning circuit includes an oscillation and detection circuit, which includes transistors Q1, Q2, resistors R4, R5, R6, R8, and capacitors C8~C10; wherein, the bases of the transistors Q1 and Q2 are connected, the emitter of Q1 is connected to the tap end through resistors R6 and R8 in turn, the collector of Q1 is grounded through capacitor C10, the collector of Q1 is connected to VCC through resistor R5, capacitors C8 and C9 are connected in parallel between the emitter of Q2 and ground, the incoming line end is connected to the emitter of Q2, the return line end is grounded, and the collector of Q2 is connected to VCC through resistor R4.

[0012] Furthermore, the conditioning circuit further includes a power supply circuit, a zero adjustment circuit, and an amplifier circuit.

[0013] A signal conditioning method for a sputtered thin film multi-directional integrated eddy current sensor, wherein resistors R4 and R5 play a role of voltage division, transistors Q1, Q2, resistors R6 and R8, capacitors C8-C10 and a sputtered thin film wire grid equivalent inductor L form an oscillation circuit, the oscillation frequency is adjusted by adjusting the capacitance of C8 and C9; the measurement distance is adjusted by adjusting the resistance of R6 and R8; R5, Q1, R6 and R8 form a detection circuit, a stable DC voltage is obtained by detection at the collector end of Q1, C10 filters the detected voltage; the detected voltage is amplified and zeroed, and finally a standard voltage signal of 0.2V-4.8V is output.

[0014] Furthermore, the wire grid signals of the five sensing surfaces are conditioned, and five standardized voltage signals are output after conditioning.

[0015] Furthermore, the amplification factor of the detected signal is adjusted by the amplifier circuit, and the amplified signal is zeroed by the zeroing circuit.

[0016] A method for preparing a sputtered thin film multi-directional integrated eddy current sensor is as follows:

[0017] 1) Ceramic matrix material processing

[0018] Choose alumina or silicon nitride ceramic materials and process them into the following Figure 1 The cube shape shown has a threaded mounting post on the top. The size of the cube can be determined according to the detection distance of the eddy current sensor. The larger the detection distance, the larger the cube size.

[0019] 2) Grinding and polishing

[0020] Use abrasive polishing fluid or polishing cloth to Figure 1 The 1st to 5th surfaces of the ceramic substrate are polished, and the roughness after polishing is less than 0.2 μm;

[0021] 3) Induction wire grid plating

[0022] Use a sputtering thin film ion plating machine to plate the induction wire grid on the 1st to 5th surfaces of the polished ceramic substrate. The shape and layout of the induction wire grid are as shown in the attached figure. Figure 2 As shown. The induction wire grid material is copper, and the temperature compensation wire grid material is nickel or platinum. The width of the induction wire grid is 1-2μm, the thickness is 0.5-1μm, and the number of turns can be determined according to the detection distance of the eddy current sensor. The greater the detection distance, the more turns. The temperature compensation wire grid is used to compensate for the temperature drift of the induction wire grid. The resistance value of the temperature compensation wire grid is R W The following formula should be satisfied:

[0023] R W ×ρ W =R Y ×ρY ——Formula 1

[0024] (R W is the temperature compensation wire grid resistance, ρ W is the temperature coefficient of the temperature compensation wire grid material, R Y is the induction wire grid resistance, ρ Y is the temperature coefficient of the sensing wire grid material)

[0025] 4) Protective film coating

[0026] After the above-mentioned induction wire grid and temperature compensation wire grid are plated, a layer of silicon nitride film is plated with a thickness of not less than 2 μm to achieve insulation protection for the wire grid film layer.

[0027] A signal conditioning method for a sputtered thin film multi-directional integrated eddy current sensor:

[0028] 1) Signal extraction

[0029] As attached Figure 2 As shown, lead pads are plated on the right side of the wire grid pattern, including the inlet terminal pad, return terminal pad and tap terminal pad of the induction wire grid. The inlet terminal pad and return terminal pad are used to supply power to the induction wire grid to form an electrical loop. The tap terminal pad is used to connect to the oscillation feedback circuit to generate feedback voltage in the circuit.

[0030] Signal conditioning first requires the induction wire grid signal to be led out. The induction wire grid can be introduced into the signal conditioning circuit through the above-mentioned pads. The signal conditioning circuit is shown in the attached figure. Figure 3 As shown, the incoming line is terminated at "L1", the return line is terminated at "L2", and the tap is terminated at "L3".

[0031] 2) Oscillator circuit

[0032] After the strain wire grid is connected to the circuit, it forms an oscillation circuit with C8, C9, Q1, Q2, and C10. C10 plays the role of starting oscillation, Q1 is used to maintain oscillation, Q2 is used for unidirectional charging, and C8, C9 and the strain wire grid form a resonant circuit. The oscillation frequency of the resonant circuit is determined by the strain wire grid inductance L and the capacitance of C8 and C9. The oscillation frequency can be calculated by the following formula:

[0033]

[0034] (f is the oscillation frequency, L is the strain gauge inductance, C8 and C9 are the inductance values ​​of C8 and C9)

[0035] Once resonance occurs, the strain wire grid emits an alternating electric field at this frequency.

[0036] 3) Feedback loop

[0037] The tap end of the strain wire grid is connected to the conditioning circuit L3, and an AC feedback voltage can be generated at the emitter stage of the transistor Q1 through R6 and R8.

[0038] 4) Detection circuit

[0039] The above feedback voltage is in AC state, and its DC component forms a DC loop with R5 and Q1. A stable DC voltage can be obtained from the collector of Q1, thereby realizing the DC function.

[0040] 5) Amplifier circuit

[0041] The DC voltage after detection needs to be amplified and zeroed to obtain a standard voltage output of 0.2V to 4.8V. The conditioning circuit uses a dual-channel operational amplifier LM158 for operation. One operational amplifier and R7 and R9 form a forward proportional operational amplifier circuit to amplify the DC voltage after detection. The amplification factor is determined by the resistance values ​​of R7 and R9 and satisfies the following formula:

[0042]

[0043] (A is the magnification, R7 and R9 are resistance values)

[0044] Another operational amplifier can perform zero adjustment on the amplified voltage signal. The zero adjustment voltage is obtained by the voltage regulator LT1763CS8-5 first stabilizing the external power supply voltage to +5V, and then dividing the voltage through R1 and R2. Adjusting the resistance values ​​of R1 and R2 can achieve zero adjustment of the amplifier circuit.

[0045] 6) Temperature compensation

[0046] The temperature compensation of the eddy current sensor described in the present invention is achieved through two aspects. On the one hand, the temperature compensation wire grid plated on the sensing surface can compensate for the temperature drift generated by the sensing wire grid. The sensing wire grid is made of metal copper. When the temperature rises, its impedance increases, which will cause the impedance of the resonant circuit composed of it, C8 and C9 to increase, resulting in a decrease in the working current of the resonant circuit and the feedback circuit. This will cause the voltage at the feedback loop end to decrease (the voltage at the emitter of Q1), resulting in a decrease in the voltage after detection and the voltage after amplification of the conditioning circuit. The temperature compensation wire grid is made of metal nickel or platinum, and its temperature coefficient is much larger than that of metal copper. When the temperature rises, the impedance of the temperature compensation wire grid will increase rapidly. The increased impedance can compensate for the voltage value of the feedback loop, ensuring that the voltage after detection and the voltage after amplification remain unchanged, thereby realizing the function of temperature compensation.

[0047] On the other hand, Q1 and Q2 in the oscillation circuit use transistors of the same type and adopt a common base working mode. When the temperature changes, the voltage difference of the transistors at the resonant end and the feedback end remains synchronized, and temperature compensation of the oscillation circuit can also be achieved.

[0048] 7) Distance adjustment

[0049] The eddy current sensor of the present invention is used to detect the distance between the metal material and the sensing surface. The detection distance can be adjusted by adjusting the resistors R6 and R8 of the feedback loop. When the resistance values ​​of R6 and R8 increase, the detection distance increases, and when the resistance values ​​of R6 and R8 decrease, the detection distance decreases.

[0050] The beneficial effects of the present invention are as follows:

[0051] 1. Multi-directional sensing

[0052] The sputtered thin film multi-directional integrated eddy current sensor described in the present invention can sputter-plate sensing wire grids on multiple surfaces of the probe ceramic base material, thereby realizing sensing of metal materials in multiple directions and having the advantage of multi-directional sensing.

[0053] 2. Miniaturization

[0054] The sputtered thin film multi-directional integrated eddy current sensor of the present invention adopts a sputtering coating process, the plated wire grid width can be as low as micron level, and the sensing wire grid can be plated in a small space. The sensor can achieve the advantage of miniaturization.

[0055] 3. High temperature resistance

[0056] The present invention discloses a sputtered thin film multi-directional integrated eddy current sensor, wherein the sensor probe is made of aluminum oxide or silicon nitride ceramic material, the induction wire grid material is metal copper, and the temperature compensation wire grid material is metal nickel or metal platinum. The above materials are all resistant to high temperatures, and the sensor probe manufactured by the sensor probe has the advantage of being resistant to high temperatures.

[0057] 4. High reliability

[0058] The sputtered thin film multi-directional integrated eddy current sensor described in the present invention has inductive wire grids plated on multiple surfaces of the sensor probe. When applied to robot dexterous hands or metal obstacle avoidance, if the inductive wire grid in one direction fails, it can be rotated and switched to other inductive surfaces for replacement. Therefore, the sensor has the characteristics of multi-channel redundancy and has higher reliability when used.

[0059] 5. Temperature self-compensation

[0060] The sputtered thin film multi-directional integrated eddy current sensor of the present invention is plated with a temperature compensation wire grid while the sensing wire grid is plated. The temperature compensation wire grid is used to compensate for the temperature drift of the sensing wire grid. When the ambient temperature changes, the eddy current sensor has the function of temperature self-compensation;

[0061] 6. Convenient signal conditioning

[0062] The signal conditioning method of a sputtered thin film multi-directional integrated eddy current sensor described in the present invention can adjust the oscillation frequency by adjusting the resonant capacitor, can adjust the amplification factor by adjusting the resistance ratio of the amplifier circuit, can adjust the output zero position by adjusting the resistance ratio of the zero adjustment circuit, and can adjust the sensor detection distance by adjusting the feedback loop resistance, which has the advantage of convenient signal adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 Schematic diagram of the sensor probe of the present invention.

[0064] Figure 2 This is the wire grid pattern of the sensor probe of the present invention.

[0065] Figure 3 The sensor signal conditioning circuit diagram (single path) of the present invention.

[0066] Typical Implementation

[0067] With reference to the sputtered thin film multi-directional integrated eddy current sensor described in the present invention, a specific implementation method is described with typical parameters of five-directional sensing, probe side length of 10 mm, detection distance of 20 mm, oscillation frequency of 10 kHz, output voltage of 0.2 V to 4.8 V, and operating temperature range of 20°C to 200°C.

[0068] Power supply circuit: It consists of voltage regulator LT1763CS8-5 (U1) and capacitors C2 to C5, which are used to stabilize the external voltage to +5V. C3 and C5 act as energy storage, and C2 and C4 act as filters.

[0069] Zero adjustment circuit: It is composed of operational amplifier LM158 (U2A), resistors R1, R2 and capacitor C1. C1 plays a decoupling role. By adjusting the resistance values ​​of R1 and R2, the output voltage of the operational amplifier can be adjusted, and this voltage can be used for zero adjustment of the amplifier circuit.

[0070] Oscillation and detection circuit: It is composed of transistors Q1, Q2, resistors R4~R6, R8, capacitors C8~C10 and the equivalent inductance "L" of the sputtered thin film wire grid. Among them, resistors R4 and R5 play a voltage-dividing role, and transistors Q1, Q2, resistors R6, R8, capacitors C8~C10 and the equivalent inductance "L" of the sputtered thin film wire grid form an oscillation circuit. The vibration frequency can be adjusted by adjusting the capacitance of C8 and C9. The measurement distance of the eddy current sensor described in the invention can be adjusted by adjusting the resistance of R6 and R8. At the same time, R5, Q1, R6, and R8 also constitute a detection circuit, and a stable DC voltage can be detected at the collector end of Q1. C10 can filter the voltage after detection.

[0071] Amplifier circuit: The amplifier circuit consists of an operational amplifier LM158 (U2B), resistors R7 and R9, and is used to amplify the DC voltage after detection. The amplifier gain can be adjusted by adjusting the resistance values ​​of R7 and R9.

[0072] 1) Preparation of eddy current sensor probe

[0073] a. Ceramic material processing

[0074] Alumina ceramic material is selected to be processed into a small cube with a side length of 10 mm, and M3 threaded mounting columns are processed on the mounting surface.

[0075] b. Grinding and polishing

[0076] Use a grinding and polishing machine to polish the five sensing surfaces of the ceramic material after the above processing with a polishing cloth. The surface roughness after polishing is less than 0.2μm.

[0077] c. Wire grid plating

[0078] Based on the sensor detection distance of 20mm and the probe sensing surface side length of 10mm, it is determined that the sensing wire grid width is 2μm, the thickness is 1μm, the total number of turns is 220 turns, and the number of tap turns is 20 turns. The sensing wire grid is plated on the five sensing surfaces using a sputtering coating machine. Five sensing wire grids are integrated and plated on a square ceramic material, which can sense the distance changes in five directions at the same time, and can realize the function of multi-directional detection.

[0079] After the induction wire grid is plated, measure the wire grid inductance L G , Impedance R G , combined with the sensor operating temperature range of 20℃~200℃, the resistance value of the temperature compensation wire grid is calculated by substituting it into formula 1. The width of the temperature compensation wire grid is 2μm and the thickness is 1μm, and the length of the temperature compensation wire grid is calculated. Use a sputtering coating machine to complete the temperature compensation wire grid plating and lead-out pad plating on the five sensing surfaces.

[0080] d. Protective film coating

[0081] After the wire grid is plated, a layer of silicon nitride protective film is plated, and the film thickness is set to 2μm to protect the wire grid film layer.

[0082] 2) Eddy current sensor signal conditioning

[0083] a. Oscillation circuit

[0084] The sensor's oscillation frequency is 10kHz, and the measured wire grid inductance is L G , and substitute it into formula 2 to calculate the resonant capacitance value. For the convenience of procurement and production, this capacitance value can be obtained by connecting C8 and C9 in parallel.

[0085] b. Detection processing

[0086] The feedback circuit is detected using an NPN transistor BC847, and a stable DC voltage D is obtained at the collector of the transistor.

[0087] c. Amplification and zeroing

[0088] The sensor output voltage is 0.2V~4.8V. The dual operational amplifier LM158 is used to amplify the DC voltage D after detection. The amplification factor is 4.6 / D. According to the amplification factor, the ratio of resistors R7 and R9 is determined to be (4.6 / D)-1. In order to reduce thermal noise, the resistance values ​​of R7 and R9 can be set to more than 100k.

[0089] After the amplification resistance is set, test the sensor output voltage value, fix the zero adjustment resistor R2 to 100Ω, adjust the resistance of R1, and adjust the output zero position to 0.2V.

[0090] d. Distance adjustment

[0091] The target detection distance of the sensor is 20mm. The metal material to be measured is used in conjunction with the sensor probe for actual measurement. The actual detection distance of the sensor is adjusted by adjusting the resistance values ​​of R6 and R8 to approach the target value of 20mm.

[0092] As attached Figure 3 The sensor probe oscillation frequency can be adjusted by adjusting the capacitance of C8 and C9, the signal amplification factor after detection can be adjusted by adjusting the resistance of R7 and R9, the amplified signal can be zeroed by adjusting the resistance of R2 and R3, and the detection distance of the eddy current sensor can be adjusted by adjusting the resistance of R6 and R8.

[0093] The present invention belongs to the field of testing and measurement, and describes a sputtered thin film multi-directional integrated eddy current sensor and its signal conditioning method, which has the advantages of miniaturization, high temperature resistance, and multi-directional sensing, and can just solve the technical problems existing in the above-mentioned special environments and emerging fields. The eddy current sensor can detect metal materials from multiple directions. And it has the advantages of small size and high temperature resistance. It solves the problem of multi-directional sensing of metal materials in small spaces and high temperature environments, and has good application prospects in the fields of high-temperature turbine shafts, high-temperature wind wheel multi-directional vibration displacement monitoring, closed and narrow pipeline flaw detection, robotic arm motion control, dexterous robotic hand touch perception, obstacle avoidance, etc.

Claims

1. A sputtered thin film multi-directional integrated eddy current sensor, characterized in that: It includes a sputtered thin film sensing probe and a conditioning circuit, wherein the sputtered thin film sensing probe is realized by plating a sensing wire grid on a ceramic material through the sputtered thin film technology, and the sensing wire grid is used to sense the distance to the external metal material; the conditioning circuit includes a resonant capacitor, and the resonant capacitor and a single sensing wire grid are equivalent to an inductor L to form an LC resonant circuit; when resonating, the sensing wire grid emits an alternating electric field outward, and the alternating electric field will produce an alternating magnetic field in space; when metal approaches, the alternating magnetic field will generate eddy currents on the metal surface, and the eddy currents will generate a magnetic field in the opposite direction, affecting the electric field of the sensing wire grid and causing the electrical characteristics of the sensing wire grid to change, and the conditioning circuit detects the change to detect the distance between the sensing wire grid and the metal being measured.

2. A sputtered thin film multi-directional integrated eddy current sensor according to claim 1, characterized in that: The ceramic material is square, and an induction wire grid is plated on any one or more surfaces; the minimum wire grid width is micron level; the ceramic matrix is ​​aluminum oxide or silicon nitride material.

3. A sputtered thin film multi-directional integrated eddy current sensor according to claim 1, characterized in that: A temperature compensating wire grid is plated at the same time as the induction wire grid is plated. The temperature compensating wire grid is used to compensate for the temperature drift of the induction wire grid. The plated induction wire grid and its temperature compensating wire grid are both made of high-temperature resistant metal materials; one end of the temperature compensating wire grid is connected to one end of the induction wire grid, and the other end of the temperature compensating wire grid is connected to the incoming line end pad, and the other end of the induction wire grid is connected to the return line end pad. The incoming line end pad and the return line end pad are used to supply power to the induction wire grid to form an electrical circuit, and then the tap end pad is led out from the induction wire grid to connect to the oscillation and detection circuit to generate a feedback voltage.

4. A sputtered thin film multi-directional integrated eddy current sensor according to any one of claims 1 to 3, characterized in that: The conditioning circuit includes an oscillation and detection circuit, which includes transistors Q1, Q2, resistors R4, R5, R6, R8, and capacitors C8-C10; wherein the bases of the transistors Q1 and Q2 are connected, the emitter of Q1 is connected to the tap end through resistors R6 and R8 in turn, the collector of Q1 is grounded through capacitor C10, the collector of Q1 is connected to VCC through resistor R5, capacitors C8 and C9 are connected in parallel between the emitter of Q2 and the ground, the incoming line end is connected to the emitter of Q2, the return line end is grounded, and the collector of Q2 is connected to VCC through resistor R4.

5. A sputtered thin film multi-directional integrated eddy current sensor according to claim 4, characterized in that: The conditioning circuit further includes a power supply circuit, a zero adjustment circuit, and an amplifier circuit.

6. A signal conditioning method for a sputtered thin film multi-directional integrated eddy current sensor, characterized in that: Resistors R4 and R5 play a voltage-dividing role, and transistors Q1, Q2, resistors R6, R8, capacitors C8~C10 and the equivalent inductance L of the sputtered thin film wire grid form an oscillation circuit. The oscillation frequency is adjusted by adjusting the capacitance of C8 and C9; the measurement distance is adjusted by adjusting the resistance of R6 and R8; at the same time, R5, Q1, R6, and R8 form a detection circuit, and a stable DC voltage is obtained by detection at the collector end of Q1. C10 filters the detected voltage; the detected voltage is amplified and zeroed, and finally a standard voltage signal of 0.2V~4.8V is output.

7. A signal conditioning method for a sputtered thin film multi-directional integrated eddy current sensor according to claim 6, characterized in that: The wire grid signals of the five sensing surfaces are conditioned and five standardized voltage signals are output after conditioning.

8. The signal conditioning method of any one of the sputtered thin film multi-directional integrated eddy current sensors according to any one of claims 6 to 7, characterized in that: The amplification factor of the detected signal is adjusted by the amplifier circuit, and the amplified signal is zeroed by the zeroing circuit.

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