138 results about "Eddy-current testing" patented technology

The invention relates to the field of electromagnetic nondestructive testing, in particular to a curved surface self-adaptive eddy current testing probe, a nondestructive flaw detector and a testing method. The eddy current detection probe comprises a magnetic core bundle, an excitation coil and an induction coil. Wherein the magnetic core bundle is formed by densely arranging a plurality of ferromagnetic magnetic needles; and the excitation coil and the induction coil radially limit the magnetic core bundle. The excitation coil is wound on one end of the magnetic core bundle away from the detection surface and is used for connecting an adjustable power supply. The exciting coil generates an alternating magnetic field for detection in a target area by using the adjustable power supply, and magnetizes the magnetic core bundle by using the adjustable power supply, so that the detection surface of the eddy current detection probe is tightly adsorbed with the target area on the surface of a detected object. And the induction coil is wound at one end, close to the detection surface, in the magnetic core bundle and is used for inducing a signal generated by a detected object in the detection process. According to the invention, the problem that the existing electromagnetic nondestructive testing probe cannot be attached to various complex curved surfaces to cause signal attenuation and influence the measurement precision is solved.

The invention discloses an eddy current testing reliability evaluation method and system based on signal space distribution characteristics, and belongs to the technical field of nondestructive testing. According to the method, eddy current signal space distribution characteristics and the detection probability (POD) and the false detection rate (PFA) in nondestructive testing reliability evaluation indexes are fused, and the method is used for comprehensively evaluating the defect detection capacity and the reliability of a detection system. By introducing the Gini coefficient to quantitatively detect the imbalance of signal space distribution, the method effectively characterizes the distinguishability of signals in a defect state and a defect-free state, and replaces traditional POD and PFA analysis methods based on single-point amplitude or phase characteristics. Compared with a traditional method, the Gini coefficient can more comprehensively represent the overall distribution characteristics of the signals, the influence of noise is small, and the method is particularly suitable for the eddy current detection environment under the condition of the low signal-to-noise ratio. Besides, a POD and PFA relation curve is constructed based on Gini coefficients, ROC analysis is performed, the defect detection rate can be effectively increased, the false detection rate can be reduced, and the reliability of the nondestructive testing system can be evaluated more efficiently and accurately.

An eddy current testing circuit, method and system, a storage medium, and a terminal belong to the technical field of eddy current non-destructive testing. A dual-path differential probe is formed mainly by combining a differential bridge and a transformer conditioning circuit, and relationships between amplitudes, phase parameters and lift-off respectively generated under alternating magnetic fields are analyzed by using signal parameters generated by a first differential signal and a second differential signal under respective alternating magnetic fields. Multi-parameter signal fusion is performed, so that the lift-off can be suppressed, and dual-path differential output achieves a high testing capability for defects under high lift-off change.

The invention belongs to the technical field of eddy current detection. The eddy current automatic detection and calibration method comprises the steps that a pose deviation matrix is calculated, a mechanical arm carrying an eddy current probe is controlled to conduct pose adjustment according to the pose deviation matrix, and the current pose of the eddy current probe is obtained; under the current pose, an inductive impedance signal caused by eddy current change of the workpiece to be detected is obtained, and associated data of the current pose and the inductive impedance signal are obtained; and performing defect positioning on the workpiece entity to be detected according to the associated data, calculating the signal-to-noise ratio of the workpiece entity to be detected in combination with a defect positioning result, performing iterative optimization on the signal-to-noise ratio within a preset time, and determining the optimal detection pose of the eddy current probe when the signal-to-noise ratio is maximum. According to the method, personal errors caused by traditional manual calibration are eliminated, the multi-attitude detection requirement of the complex curved surface workpiece can be met, and the accuracy of defect quantitative analysis is remarkably improved.

The invention discloses a production line automation defect identification method and system based on eddy current detection. The system comprises an eddy current detection probe, a motion control module, a signal processing module and the like, an alternating magnetic field is applied to a metal workpiece through a double-frequency excitation coil, the distance between the probes is dynamically controlled through a laser positioning sensor, and after signal preprocessing and defect feature extraction, a support vector machine classifier decides defect types and triggers an execution mechanism to act. According to the method, time division multiplexing dual-frequency excitation is adopted, photoelectric cooperative detection is combined, and surface topography and eddy current data are fused. The system is connected with a factory MES (Manufacturing Execution System) through a Modbus-TCP (Transmission Control Protocol) so as to realize quality tracing. According to the scheme, the problems of single-frequency detection depth limitation, high vibration false detection rate, low manual sorting efficiency and data islanding are solved.

The invention discloses a fusion device magnet coil copper conductor nondestructive testing method and a computer product, and relates to the technical field of nondestructive testing, the method comprises the following steps: obtaining original eddy current testing signals of a to-be-tested object or a plurality of areas of the to-be-tested object under specific physical conditions; preprocessing the original eddy current detection signal, wherein the preprocessing comprises denoising and signal correction; extracting features from the preprocessed signals and carrying out normalization processing; on the basis of a pre-established multi-parameter model related to the physical conditions of the to-be-tested object, theoretical signals of the to-be-tested object under various physical conditions are predicted through finite element simulation; and performing matching estimation on the normalized signal and a theoretical signal to obtain an estimated signal, and evaluating the defect existence probability based on the estimated signal. Based on an eddy current testing technology, a probe scans a sample and obtains a signal, and a finite element analysis method is combined to simulate and evaluate defects such as cracks possibly existing in a material.

The invention discloses a pulsed eddy current near-far field composite detection probe and method for coating system defects. The probe comprises a diode circuit board, a magnetic shielding structure, an electric shielding structure, a far field excitation coil, a near field excitation coil and a three-dimensional magnetic field sensor, when a functional coating system is detected, a bipolar square wave serving as an excitation signal is rectified into two square wave signals with the same parameters except polarity after passing through a diode circuit board, the two square wave signals are respectively introduced into a far-field excitation coil and a near-field excitation coil, and the two excitation coils excite an incident magnetic field in a time-sharing manner; the three-dimensional magnetic field sensor located in the center of the bottom of the probe simultaneously picks up near-field and far-field detection signals. The probe can realize pulsed eddy current detection and pulsed far-field eddy current detection at the same time, and compared with a single detection method, the probe can pick up more defect information carrying different types of damages, so that multiple signal characteristics are extracted to detect and quantitatively evaluate the coating thinning defect and the metal matrix crack defect of a functional coating system at the same time.

The invention provides an array eddy current testing method and device for rivet hole edge cracks, and belongs to the technical field of nondestructive testing. An array eddy current detection method for rivet hole edge cracks comprises the following steps: S1, probe fitting: inserting a flexible eddy current array probe into a to-be-detected rivet hole, and controlling a miniature air pressure bag to inflate, so that the probe is adaptively fitted with a hole wall; s2, a signal acquisition step: applying a multi-frequency mixed excitation signal to the probe, moving the probe in a spiral progressive scanning mode, and acquiring an eddy current response signal of the hole wall; s3, signal compensation: according to the radial distance and azimuth angle of the current position of the probe; according to the device, the flexible eddy current array probe is matched with the air pressure attaching mechanism, so that the device can adapt to rivet holes with different hole diameters, the lift-off effect is eliminated, the signal consistency is improved, a hole edge false signal is effectively inhibited by establishing an accurate electromagnetic distortion function model and performing real-time compensation, and the false alarm rate is greatly reduced.

The invention is applicable to the field of metal material nondestructive testing, and provides a method for correcting wall thickness of a small block defect in pulsed eddy current testing, which comprises the following steps: starting a pulsed eddy current testing probe, and exciting a pulsed magnetic field by the probe to induce an eddy current field in a tested metal conductor; setting a detection step length, gradually scanning and detecting the defect direction of the detected metal conductor small block by a detection probe from a starting point, and automatically calculating and acquiring a wall thickness value at each detection point position; recording an initial change detection point and an end point change detection point of the wall thickness value obtained by scanning detection, calculating the distance DSE between the initial change detection point and the end point change detection point by combining the step length, and then calculating the defect size LDEF of a small block; and the minimum value h of the wall thickness values obtained through scanning detection is taken, and the actual wall thickness value h2 of the small block defect is calculated according to a correction formula. Through the correction method, the block defects smaller than the footprint size can be correctly evaluated, and serious consequences caused by wrong evaluation of small block serious defects are avoided.

The invention provides a deployable flexible GMR eddy current testing method and system for a complex curved surface component, and relates to the technical field of nondestructive testing. The method comprises the following steps: establishing a curved surface coordinate system and an expansion domain coordinate system, constructing a geometric mapping relation of a flexible sensing array, and performing clearance compensation, attitude correction and temperature drift correction on multi-frequency response data in an expansion domain to form a unified response data set; defect response distribution is generated through robust reconstruction and reprojected to the curved surface coordinate system, and space positioning and size and orientation recognition of defects are achieved; and adaptively updating the attitude, the path and the excitation scheme in combination with the fitting state parameters until the detection coverage and the confidence meet the requirements. According to the method, high-precision detection and process traceability of the defects of the complex curved surface component are realized.

The invention relates to the technical field of nondestructive testing, and discloses a method for automatically adjusting an eddy current testing system by using binocular video measurement, an integrated binocular video measurement and array eddy current sensor and instrument are adopted, when the method is used, the video binocular sensor is in front, and a surface three-dimensional image of a current detection area of a to-be-detected welding seam is obtained; according to the method, real-time measurement and evaluation are carried out according to a welding seam or a rough surface, sensitivity parameters of the array eddy current instrument are adjusted, meanwhile, binocular video AI judgment and auxiliary detection are used for correcting material surface discontinuity information of eddy current imaging of the detected welding seam or an object, and therefore the purpose of reliable and rapid nondestructive testing is achieved.

The invention provides a weld joint dynamic eddy current detection method and system based on reinforcement learning, the system comprises a sensing layer, a decision layer, an execution layer and an identification layer, the sensing layer is used for collecting detection data of a weld joint surface, and the sensing layer comprises an eddy current sensor, a laser displacement meter and a thermal infrared imager; the decision-making layer is connected with the sensing layer and is used for dynamically adjusting detection parameters based on a reinforcement learning algorithm; the execution layer is connected with the decision layer, is used for executing a detection action according to the adjusted detection parameters, and comprises a four-axis linkage eddy current sensor and a frequency converter; the identification layer is connected with the sensing layer and the decision-making layer, is used for identifying weld defects based on the eddy current signals, and comprises a multi-defect identification model; and the decision layer dynamically adjusts detection parameters of the execution layer through a reinforcement learning algorithm by taking the time-frequency characteristic of the eddy current signal, the lift-off gap and the environment temperature as a state space and taking the frequency adjustment amount and the lift-off gap control instruction as an action space, so that real-time detection of the apparent defects of the welding seam is realized.

The invention relates to the technical field of nondestructive testing, and discloses a long-distance eddy current testing probe, the long-distance eddy current testing probe comprises a cable assembly and a probe assembly, the probe assembly is connected to the far end of the cable assembly, and the probe assembly comprises a coil assembly, a pre-amplifier, a power supply conversion module and a signal shunt module. The pre-amplifier is connected to the coil assembly to amplify a detection signal; and the power supply conversion module is used for converting an excitation signal of the eddy current instrument into a bipolar direct-current power supply and supplying power to the pre-amplifier. Based on the compatibility of the excitation signal of the eddy current instrument and the pre-amplifier of the eddy current sensor in power parameters, an excitation signal multiplexing power supply method is adopted, an extra power line is avoided, and the problems of signal attenuation compensation and power supply in long-distance eddy current detection are effectively solved.

A kind of eddy current testing probe and method for identifying any crack and direction around hole, the probe includes a pie-shaped detection coil with middle magnetic core, the magnetic core not only ensures accurate positioning, but also uses magnetic collection effect by enhancing coil inductance, to strengthen the magnetic field inside and back of hole.The probe is also equipped with three layers of excitation coil, one layer and two layers of coil are arranged orthogonally, three layers and one layer of coil are at an angle of 135 °, realize the efficient detection of any direction crack and identify the direction of any crack defect.The flexible support of probe enables it to adapt to curved surface structure, widen the application range.The detection method uses orthogonal differential technology, uses the symmetry of hole structure to identify defects around hole, significantly improve the detection sensitivity of defects on the back and inside of hole structure.Compared with traditional surface and near-surface defect eddy current testing technology, the present application provides a more effective solution for high-precision detection of hole structure through innovative coil configuration and defect identification method.

The invention provides an L1 regularization eddy current defect imaging method based on closed-loop fractional order PID control, and relates to the field of electromagnetic eddy current detection.The method comprises the steps that defect imaging is carried out on collected eddy current data through an array eddy current sensor by means of the L1 regularization eddy current defect imaging method based on closed-loop fractional order PID control; defect position information of the metal material in a damaged state is theoretically obtained, and quantitative evaluation is carried out on defects. According to the imaging method disclosed by the invention, defect space distribution after multiple times of iterative optimization is highly matched with actually measured data, the defect characteristics of the metal component in a damaged state can be effectively positioned and evaluated, the non-contact detection characteristic eliminates the dependence on a mechanical scanning device, and the implementation is convenient.

The invention relates to the technical field of aero-engine nondestructive testing, and discloses an aero-engine support plate blade in-situ eddy current testing device and a testing method thereof, and the aero-engine support plate blade in-situ eddy current testing device comprises a handle, a telescopic probe rod and a testing end. The detection end is rotationally connected with the telescopic probe rod and comprises an adjusting swing block, a supporting end base, a clamping and positioning assembly and a transmission detection mechanism. The clamping and positioning assembly adopts a V-shaped fork block design, and can adapt to the shape and thickness of the blade for clamping, so that the detection end and the blade are kept stable. The transmission detection mechanism is composed of a miniature lead screw, a linear guide rail, an anti-backlash gear set and a servo motor and drives the detection probe assembly to accurately move along the surface of the blade. The detection probe adopts a leaf spring to support a flexible array eddy current sensor, and self-adaptive adjustment can be realized to ensure that the detection surface is tightly attached to the curved surface of the blade. The invention provides a device and a method capable of realizing rapid, full-area and high-sensitivity in-situ eddy current detection on a support plate blade under the condition that an engine is not disassembled and adaptive to air inlet space constraint.

The utility model relates to detection equipment for a chemical agent for metal, which comprises a seat body I, the upper end of the seat body I is connected with a three-axis moving platform, and the interior of the seat body I is fixedly connected with a drying box, a weight measuring part, an oil coating part and a cleaning test component; one side of the Z-axis moving end of the three-axis moving platform is fixedly connected with a swing test assembly, and the swing test assembly comprises a reciprocating swing unit; the reciprocating swing unit comprises a first motor, a third rotary disc, a rod body, a swing rod, a third movable groove and an electric clamping jaw. The cleaning test assembly comprises a shell II, a cavity, a cover body, an opening and an eddy current test assisting unit; the eddy current testing assisting unit comprises a second motor, a second rotating disc rotationally connected to the inner wall of the cavity, a first rotating disc rotationally connected to the lower end of the cover body, and a column body connected between the first rotating disc and the second rotating disc. Compared with the prior art, the dynamic condition of a workpiece in actual use can be simulated, different working conditions can be simulated, the test result has higher application value, cleaning process parameters are accurately verified and optimized, and universality is achieved.

An eddy current testing apparatus and associated method for performing nondestructive testing of heat exchanger tubes accessible through the tubesheet. The apparatus includes a motor-driven drive pulley and one or more idler pulleys that engage a test cable of a test probe, feeding the test cable and test head into and retrieving the test cable and test head from within the heat exchanger tube under test. The apparatus' support bracket includes a manually expandable tube clamp operated by an actuation lever. The clamp includes a tubular locking sleeve with an expandable portion that inserts into and releasably locks onto an anchor tube in the tubesheet, thereby cantilevering the apparatus from the tubesheet. The idler pulley is attached to a motor-driven pivot arm, which is movable between an inward position that presses the test cable against the drive pulley and an outward position that releases the cable for easy setup or removal.

The invention belongs to the technical field of eddy current detection. According to the eddy current detection device and method for the annular piece, a multi-channel profiling eddy current sensor can horizontally move and rotate along the center axis of the annular piece, the detection width is smaller than the width of a groove, and the multi-channel profiling eddy current sensor is provided with a first alternating magnetic field generation assembly and a second alternating magnetic field generation assembly; the flexible array eddy-current sensor and the single-channel profiling eddy-current sensor are respectively provided with a third alternating magnetic field generating assembly matched with the outer surface of the annular piece with smaller curvature change and a fourth alternating magnetic field generating assembly matched with the outer surface of the annular piece with larger curvature change; the four alternating magnetic field generation assemblies are all of a differential eddy current coil circuit connection structure. The problems that the omission ratio is high due to the fact that a common rigid probe and a fixed path are difficult to match with the complex curved surface of the annular part, the false alarm rate is increased due to paint layer noise and electromagnetic interference of the annular part, and the manual detection efficiency is low can be solved, the detection efficiency is improved, and omission and false detection are avoided.

The utility model relates to a device for improving the semi-automatic eddy current detection stability of a heat transfer tube with a tube plate structure, which comprises a handheld gun head driver, an eddy current flaw detector probe, a positioning assistor and a plane position fixing wheel, the positioning assistor, the eddy current flaw detector probe and the plane position fixing wheel are all installed at the output end of the handheld gun head driver, the positioning assistor is used for achieving centering of the eddy current flaw detector probe after being inserted into a pipe hole, and the plane position fixing wheel is used for limiting the positioning assistor to be arranged in the pipe hole to keep the preset depth. When the semi-automatic eddy current detection device is used for carrying out semi-automatic eddy current detection on a heat transfer tube, a detector can realize quick positioning of a tube hole to be detected through the positioning assistor and the plane fixing wheel which are additionally arranged at the gun head; and meanwhile, the positioning assistor and the plane fixing wheel can reduce the load on the arm caused by holding the gun head driver for a long time, so that the detection stability is greatly improved, and the detection efficiency is greatly improved.

To provide a coil module, a probe for detecting an eddy current, and an eddy current detector which can be manufactured at low cost in a short time.SOLUTION: The coil module includes: a cross coil having a first coil forming an annular shape surrounding a first axial line, and a second coil forming an annular shape surrounding a second axial line intersecting the first axial line and covering a part of an outer peripheral side of the first coil; and a coil holder having a storage recessed part for holding a plurality of cross coils formed in a state where a plurality of cross coils are arrayed in an arraying direction extending in a direction intersecting with the first axial line and the second axial line in a surface formed by the first axial line and the second axial line. In a pair of cross coils adjacent to each other in the arraying direction, the first coil of the cross coil on one side faces the second coil of the cross coil on the other side, and the second coil of the cross coil on one side faces the first coil of the cross coil on the other side.SELECTED DRAWING: Figure 3

The present application relates to the field of hollow shaft detection, and relates to a high-speed rail hollow shaft inner hole array eddy current detection system, which does not need to adopt a shaft hole end adapter and a take-up motor, does not need manual adjustment centering, can realize fast alignment detection and fast take-up, and comprises a moving trolley, a controller, a display and a detection device, the detection device comprises a shell and take-up, push detection, guiding structure, the take-up structure adopts a three-section slide rail type guide groove with variable diameter, the detection probe in the push detection structure is conical and can be replaced by pulling and inserting, the detection line adopts nylon tube packaging, the guiding structure is arranged at the probe outlet end of the shell and is used for guiding the probe into the inner hole of the hollow shaft, the guiding structure can be expanded to adapt to hollow shafts with different structures and sizes, and a laser centering assembly is additionally arranged to realize automatic centering of the detection probe and the inner hole. The present application optimizes the structure and performance of the existing array eddy current detection device, saves production manufacturing cost, and has a simpler overall structure and is easier to operate, and the detection result is accurate and reliable.

The utility model provides an eddy current testing device for a variable-diameter shaft, which comprises a probe movement control mechanism, a probe clamping mechanism, a probe library, a sample block library and a workpiece rotating table, and the probe library, the sample block library and the workpiece rotating table are arranged corresponding to the movement track of the probe movement control mechanism; the probe library is provided with a plurality of probe fixing rings for storing eddy current probes, the sample block library comprises a mounting vertical plate and a plurality of profiling test blocks assembled on the mounting vertical plate, and the workpiece rotating table comprises a first rotating table and a workpiece clamp mounted on the first rotating table; and the probe movement control mechanism is connected with the probe clamping mechanism so as to drive the probe clamping mechanism to be switched among the probe library, the sample block library and the workpiece rotating table. And the mechanical detection of the variable-diameter shaft can be realized.

The present application relates to the technical field of nondestructive testing, and provides a kind of dynamic characteristic eddy current detection system and method of scraper chain to solve the problems of low detection efficiency, unable to measure tension and speed synchronously, and probe is easily damaged in harsh environment and inconvenient to maintain, etc.The technical scheme of the system mainly includes: probe detection unit, adopts built-in iron core array coil layout, synchronously induces dynamic eddy current determined by chain speed and induced eddy current caused by tension change;Detection protection unit is provided with upper and lower open and close maintenance opening for quick maintenance;And detection lift-off regulation unit can accurately adjust the distance between probe and chain.The present application can realize the online synchronization, high-precision monitoring of scraper chain tension and speed, significantly improve the detection efficiency and reliability, and at the same time enhance the environmental adaptability and maintenance convenience of the system, and provide effective support for intelligent operation and maintenance of scraper conveyor.

The present invention discloses a synchronous pulley eddy current detector, which relates to the field of eddy current detection equipment. The key points of its technical solution are as follows: It includes a frame, a feeding conveyor line, a good product discharging conveyor line, a defective product conveyor line, a horizontal panel, a feeding transfer module, and a discharging transfer module provided on the frame. On one side of the horizontal panel on the frame, an outer peripheral surface eddy current detection component, an inner peripheral surface eddy current detection component, an upper end surface eddy current detection component, a flipping component, and a lower end surface eddy current detection component are sequentially arranged from the feeding conveyor line towards the good product discharging conveyor line direction. Three-jaw chucks are respectively arranged on the frame. An elevating drive component for driving the vertical lifting of the rotating table and a pulley drive component for driving the rotation of the rotating table are also arranged on the frame. Slots for the three-jaw chucks to extend out are respectively arranged on the horizontal panel. A fork-type transfer mechanism is arranged on the other side of the horizontal panel on the frame. The present invention effectively improves the eddy current detection efficiency of products.

The present invention provides a combined detection method for metal component surface defects, which relates to the field of metal detection and includes: step S1, workpiece placement; step S2, eddy current testing; step S3, workpiece transfer; step S4, visual inspection; and step S5, workpiece judgment. This method combines eddy current and machine vision to analyze and judge the surface defects of thin-walled tubular or cylindrical metal components. This effectively addresses the problems of single machine vision detection methods being unable to accurately and quickly detect surface defects of such metal components, prone to detection blind spots, and single eddy current flaw detection being insensitive, quantitatively inaccurate, and susceptible to signal interference. This method achieves efficient, accurate, and comprehensive surface flaw detection of metal components.

The present invention relates to an eddy current nondestructive testing method for quantitatively measuring the penetration depth of liquid rocket engine injector welds. The principle is that when a probe coil carrying an alternating current approaches the weld surface, the primary excitation magnetic field induced by the probe coil generates an induced current in the conductor being tested, referred to as an eddy current. The eddy current then generates a secondary induced magnetic field in the opposite direction of the primary magnetic field, affecting the coil impedance signal. By analyzing the change in this impedance, defect information and quantitative analysis of the conductor being tested can be obtained. The present invention utilizes a spring-shaped, self-excited, self-testing probe coil concentrically arranged on the injector weld ring, as well as an eddy current testing experimental system, assisted by a four-axis mechanical scanning device. The method of the present invention can effectively evaluate welds with complex surface shapes and internal surface defects, has better detection capabilities and sensitivity, and has the advantages of high detection rate, fast detection speed, and high efficiency.

The invention provides a pulsed eddy current detection device and detection method based on roller pair adjustment, and relates to the technical field of nondestructive detection. The device comprises a supporting frame, a roller pair, a telescopic driving mechanism, a detection probe, a sliding adjusting mechanism, a distance measuring unit and a control unit. The control unit maintains the constant distance between the detection probe and the surface of the detected rod body based on a feedback signal of the distance measuring unit; based on the distance and the roller state signal, a telescopic driving mechanism is controlled to adjust the posture of the roller pair, so that the axis of the roller pair is aligned with the axis of the measured rod body; and when a preset spacing stability condition and an alignment condition are met, controlling the detection probe to transmit a pulsed eddy current excitation signal to the detected rod body, and receiving and outputting an eddy current response signal for defect identification. The double-shaft lift-off effect is actively inhibited through dynamic closed-loop control, the stability and accuracy of a detection signal are guaranteed, and then the recognition rate and detection reliability of the rod body surface and near-surface defects are remarkably improved.

This application provides a compressed air supply mechanism, belonging to the field of eddy current testing technology, which can improve the pressure stability of the supplied compressed air, as well as the stability and accuracy of eddy current test results, and improve testing efficiency. The compressed air supply mechanism includes a supply pipeline, a compressor, a series-connected air storage unit, a multi-stage gradient filtration unit, and a multi-stage drying unit. The series-connected air storage unit is used to store the compressed air supplied by the compressor, precipitate impurities in the compressed air, and stabilize the pressure of the compressed air. The multi-stage gradient filtration unit includes multiple filtration modules and is used to further remove impurities and moisture from the compressed air. The multi-stage drying unit includes multiple drying modules and is used to remove moisture from the compressed air. The filtration modules, drying modules, and series-connected air storage unit are arranged alternately to enhance the filtration effect. This application also provides an eddy current testing system.

Method for eddy current testing of cast components (100) in a production line, wherein the cast components (100) are tested individually, comprising the steps: - Arranging the cast component (100) to be tested in a holder (300) which has at least two eddy current sensors (310); - Measuring local electrical conductivities of the cast component (100), for which each eddy current sensor (310) performs at least one measurement; - Evaluating the measurements, for which the measured values ​​of each eddy current sensor (310) are compared with a specific target value range (S), whereby the correct position of the cast component (100) arranged in the holder (300) is first detected using the eddy current sensors (310) and the measurements are then started automatically; - Evaluate the cast component (100) as defective if at least one measured value is outside the specific target value range (S), otherwise evaluate the cast component (100) as free of defects.