CN103486960A - Ultrasonic, vortex and EMAT integrated lossless thickness tester and method thereof - Google Patents

Abstract

The invention relates to an ultrasonic, eddy current and EMAT integrated non-destructive thickness gauge and method thereof, which includes an excitation module, a receiving preprocessing module, an analog switch, an A/D converter, a self-checking module, a microcontroller MCU, and a CPU Module, power supply module, CPU peripheral display storage, the excitation module is connected with the receiving preprocessing module, the receiving preprocessing module is connected with the analog switch, the analog switch is connected with the A/D converter, and the A/D conversion The device is connected with the microcontroller MCU, the self-checking module is connected with the microcontroller MCU, the excitation module includes an ultrasonic excitation module, an eddy current excitation module and an EMAT excitation module; the receiving preprocessing module includes an ultrasonic receiving preprocessing module , Eddy current receiving preprocessing module and EMAT receiving preprocessing module. The invention increases the comparability of the measurement results by combining the ultrasonic wave, the eddy current and the EMAT, reduces the misjudgment rate in the single-method measurement, and simultaneously overcomes the limitation of the single-method measurement.

Description

An ultrasonic, eddy current and EMAT integrated non-destructive thickness gauge and method thereof

technical field

The invention belongs to the technical field of nondestructive testing, and relates to an ultrasonic, eddy current and EMAT integrated nondestructive thickness gauge and a method thereof.

Background technique

The long-term use of ferromagnetic pressure-bearing pipes and containers with cladding layers will cause wall thickness reduction due to corrosion. When the wall thickness reduction reaches a certain level, it may fail, resulting in huge economic losses, and even casualties. occur. Therefore, it is very important to measure the thickness of equipment products such as pipelines for oil, water, gas and other media. At the same time, in industrial production and application, it is necessary to quickly and randomly measure the thickness of equipment or products. Large-scale equipment or online systems are difficult to meet the requirements. This requires a portable thickness gauge to achieve high precision, safety and reliability. Non-destructive measurement.

The current thickness gauges have their own advantages and disadvantages and scope of application. Ultrasonic thickness measurement technology has good directionality, strong penetrating ability, short wavelength, small diffraction phenomenon, high energy, focusing and diverging effects, wide application and strong adaptability. , but a coupling agent (water, glycerin, etc.) is required for measurement, which is likely to cause environmental pollution. At the same time, a good coupling between the ultrasonic sensor and the metal body is required. The coating structure is damaged and the operation is inconvenient, which affects the efficiency of ultrasonic thickness measurement and limits the application field. In practical applications, it is suitable for thickness measurement of various materials such as metals, non-metals, and composite materials. For example, the Chinese patent application number is 201020274870.5 for the utility model patent "ultrasonic thickness gauge", the Chinese patent application number is 201120306354.05 for the utility model patent "ultrasonic coating thickness gauge", the Chinese patent application number is 201120225836.3 for the utility model patent "a Ultrasonic Thickness Gauge”, the Chinese patent application number is 200920246432.5 utility model patent “An Ultrasonic Thickness Gauge”.

Eddy current thickness measurement technology has the advantages of fast speed, non-contact, wide spectrum, rich information, easy manufacturing, and simple detection circuit. However, due to the skin effect, it is difficult to detect the deeper information of the test piece. However, there are still deficiencies in the thickness detection of large-area and large-wall-thickness specimens. Eddy current thickness measurement is divided into three types according to the difference of coating material and base material: composite coating thickness measurement, non-conductive layer thickness measurement on non-magnetic metal and non-magnetic coating thickness measurement on magnetic metal. In practical applications, it is mainly used to measure the oxide or coating thickness on the surface of aluminum profiles, aluminum plates, aluminum tubes, aluminum-plastic plates, and aluminum workpieces. For example, the Chinese patent application number is 201120184897.X utility model patent "a new type of eddy current sensor thickness gauge", the Chinese patent application number is 201120184916.9 utility model patent "a pulse eddy current thickness gauge".

EMAT (Electromagnetic Acoustic Transducer) is a device that excites and detects ultrasonic waves in a magnetic material. It uses the principle of electromagnetic induction to directly excite ultrasonic waves in the detected body. This technology does not require couplant or close contact with the metal surface. It realizes non-contact measurement, simplifies operation, and has high detection sensitivity. At the same time, EMAT can flexibly change the excited and received wave modes. The material in the covered state is tested. EMAT is mainly developed based on two mechanisms: Lorentz force and magnetostrictive effect. The Lorentz force mechanism is suitable for metallic materials, and for ferromagnetic materials, the magnetostrictive effect mechanism is dominant. Therefore, the EMAT based on the Lorentz force mechanism is generally applied to non-ferromagnetic materials (aluminum, copper, etc.), and the detection of ferromagnetic materials mainly uses the EMAT of the magnetostrictive effect mechanism. At present, this technology has been studied in stages in China. For example, the Chinese patent application number is 92222396.3 "portable thickness gauge" and the Chinese patent application number is 200810226405.1 "electromagnetic ultrasonic thickness measurement method". Permanent magnets are used to provide magnetic fields, which is not convenient for iron The thickness of magnetic materials is measured. The EMAT in the Chinese patent application No. 93206367.5 "Electromagnetic Ultrasonic Thickness Gauge" uses U-shaped soft iron, and the size of the transducer is relatively large, which is inconvenient to use.

With the rapid development of modern technology, the detection requirements for components in important industrial fields such as aerospace, nuclear power, ships, petroleum, chemical industry, natural gas, bridges, etc. are getting higher and higher. Single-function thickness measurement technology can no longer meet social needs. , a multi-functional thickness measurement system is needed, which uses multiple different thickness measurement methods to measure thickness at the same time, making the measurement results more convincing, avoiding mismeasurement caused by only one thickness measurement method, and making up for the shortcomings of single function detection. insufficient.

Contents of the invention

The main purpose of the present invention is to propose an ultrasonic, eddy current and EMAT integrated non-destructive thickness gauge and its thickness measurement method based on the existing theory of nondestructive testing, combined with today's mainstream thickness measurement technology, through ultrasonic, eddy current and EMAT The combination of the three provides three measurement methods for non-destructive measurement of the thickness of the same specimen, which increases the comparability of measurement results, reduces the misjudgment rate of single-method measurement, and overcomes the limitations of single-method measurement. The method with large deviation of measurement results realizes the function of active self-checking (correction), which overcomes the shortcomings in the prior art.

In order to achieve the above object, the technical solution of the present invention is: an ultrasonic, eddy current and EMAT integrated nondestructive thickness gauge, the difference is that it includes an excitation module, a receiving preprocessing module, an analog switch, and an A/D converter , self-verification module, microcontroller MCU, CPU module, power supply module, CPU peripheral display storage, the excitation module is connected with the receiving preprocessing module, and the receiving preprocessing module is connected with the analog switch, and the analog switch is connected with A The /D converter is connected, the A/D converter is connected with the microcontroller MCU, the self-checking module is connected with the microcontroller MCU, the microcontroller MCU is connected with the CPU module, and the CPU module is connected with the microcontroller MCU respectively. The display screen, communication interface, alarm module, and data storage module are connected, and the excitation module includes an ultrasonic excitation module, an eddy current excitation module and an EMAT excitation module; the receiving preprocessing module includes an ultrasonic receiving preprocessing module, an eddy current receiving preprocessing module and EMAT receives the preprocessing module.

According to the above scheme, the ultrasonic excitation module is composed of a signal generator, a drive circuit, a high-voltage switch circuit, and an ultrasonic sensor, and the ultrasonic signal receiving preprocessing module is composed of a preamplifier circuit, a band-pass filter circuit, and a program-controlled automatic gain circuit. The signal generator is connected to a drive circuit, the drive circuit is connected to a high-voltage switch circuit, the high-voltage switch circuit is connected to an ultrasonic sensor, the ultrasonic sensor is connected to a preamplifier circuit, and the preamplifier circuit is connected to a bandpass The filter circuit is connected, and the band-pass filter circuit is connected with the program-controlled automatic gain circuit.

According to the above scheme, the eddy current excitation module is composed of a signal generator, a power amplifier, and an eddy current sensor, and the eddy current signal receiving preprocessing module is composed of a detection circuit, a balanced filter circuit and an adjustable gain amplifier circuit. The power amplifier is connected to the eddy current sensor, the eddy current sensor is connected to the detection circuit, the detection circuit is connected to the balance filter circuit, and the balance filter circuit is connected to the adjustable gain amplifier circuit.

According to the above scheme, the EMAT excitation module is composed of a signal generator, a drive circuit, a class D power amplifier circuit, a matching circuit, and an electromagnetic acoustic transducer EMAT, and the EMAT signal receiving preprocessing module is composed of a matching circuit, a preamplifier circuit , a band-pass filter circuit, and a program-controlled automatic gain circuit, the signal generator is connected to a driving circuit, the driving circuit is connected to a class D power amplifier circuit, the class D power amplifier circuit is connected to a matching circuit, and the matching circuit It is connected with the electromagnetic acoustic transducer EMAT, and the electromagnetic acoustic transducer EMAT is connected with a matching circuit, and the matching circuit is connected with a preamplifier circuit, and the preamplifier circuit is connected with a bandpass filter circuit, and the bandpass The filter circuit is connected with the program-controlled automatic gain circuit.

According to the above scheme, the ultrasonic sensor is arranged in the ultrasonic probe, the ultrasonic probe is an integrated transceiver, the ultrasonic sensor is composed of bimorph chips, one chip is used to transmit ultrasonic waves, and the other chip is used to receive ultrasonic waves.

According to the above scheme, the eddy current sensor is arranged in the eddy current probe, the eddy current probe is a transceiver integrated type, the outside of the eddy current sensor adopts a shielded structure, the eddy current sensor is composed of two sets of coil windings, and one set of coil windings is the transmitting coil winding , the other group is the receiving coil winding, the input end of the transmitting coil winding is connected to the output of the excitation module, and the receiving coil winding is connected to the input of the receiving preprocessing module.

According to the above scheme, the electromagnetic acoustic transducer EMAT is arranged in the EMAT probe, and the described EMAT probe is a transceiver integrated type, and the outside of the electromagnetic acoustic transducer EMAT adopts a shielded structure, and the electromagnetic acoustic transducer EMAT consists of two groups Composed of coil windings, one set of coil windings is a transmitting coil winding, and the other set is a receiving coil winding, the input end of the transmitting coil winding is connected to the output of the excitation module, and the receiving coil winding is connected to the input of the receiving preprocessing module.

An integrated non-destructive thickness measurement method of ultrasonic wave, eddy current and EMAT, the difference is that the method comprises the following steps:

Step A), select one of the three non-destructive measurement modes of ultrasonic, eddy current and EMAT to be detected, and place the corresponding probe on the test piece;

Step B), the signal generator is controlled by the microcontroller MCU to generate the excitation signal of the required specific frequency, and the transmitter end of the probe is excited after the power is amplified;

Step C), according to the respective excitation principles of ultrasonic wave, eddy current and EMAT, a voltage signal is induced at the receiving end of the probe, and the voltage signal is processed by the receiving preprocessing module to pick up the signal;

Step D), the analog signal obtained after processing is sent to the A/D converter through the analog switch to be converted into a digital signal, and the measured thickness value of the test piece is displayed and stored after being processed by the CPU module;

Step E), when the three methods of ultrasonic, eddy current and EMAT are used to measure the same test piece respectively, start the self-verification program, and compare the measurement results of the three non-destructive thickness measurement methods with each other through the self-verification module, Realize the active self-calibration function for methods with large deviations in measurement results.

In the present invention, the signal generator is controlled by a microcontroller MCU to generate an excitation signal of a specific frequency required for ultrasonic thickness measurement, eddy current thickness measurement, and EMAT thickness measurement. The signal is amplified by power to excite the probe coil, and the signal received by the probe coil is sent into The corresponding detection channel loads the signal to the corresponding ultrasonic, eddy current, and EMAT sensors, so that each sensor can complete the pickup of the signal containing the information about the thickness of the test piece. After the information is picked up, it is sent to the receiving preprocessing module of ultrasonic, eddy current, and EMAT to process the picked up signal, and the processed analog signal is sent to the A/D converter through the analog switch, and the analog signal representing the thickness of the test piece is converted into Digital signal, the measurement data is sent to the CPU module according to the CPU demand. The CPU module displays and stores the measured thickness value of the test piece on the display, and compares it with the threshold value, and starts the alarm unit if it exceeds the range. Whenever the same test piece is measured by the three methods of ultrasonic, eddy current and EMAT, the self-calibration program is started, and the three measurement data are sent to the self-calibration circuit for calibration. At the same time, the calibrator performs self-calibration The output value of the circuit is compared and judged in pairs. If the three measurement data are within the error range, no processing will be performed; if a certain measurement data has a large deviation, the calibrator will give an error indication and send it to the microcontroller MCU for error channel calibration. deal with. The error indication, error channel and calibration completion command generated during the self-checking process are sent to the CPU module synchronously, and are displayed on the display to notify the user.

Based on the above technical scheme, the present invention has the following advantages:

1. The present invention integrates ultrasonic, eddy current and EMAT detection into one. When measuring the thickness of the same test piece, three methods can be selected, which reduces the misjudgment rate when measuring with a single method, and improves the accuracy and credibility of the measurement. Spend;

2. The present invention compares the measurement results of the three non-destructive thickness measurement methods with each other arbitrarily through the self-verification module, and realizes the active self-verification (validation) function of the method with a large deviation in the measurement results, which greatly improves the accuracy of the measurement results. accuracy;

3. The present invention integrates ultrasonic, eddy current and EMAT detections. Compared with the separate ultrasonic thickness gauges, eddy current thickness gauges, and EMAT thickness gauges, a set of CPU modules, memory chips, display screens, power supply systems, The data processing system and casing, etc., greatly save the cost of equipment, realize the sharing of resources and the complementary advantages between technologies;

4. The present invention has high integration, small size, light weight, easy operation and portability. For different test pieces, there are three non-destructive testing methods to choose from, which has a wide range of applications and overcomes the limitations of a single non-destructive testing method. Suitable for use in various harsh environments;

5. The present invention archives and stores data through local and remote databases, and can call data at any time to evaluate the health status of the test piece and perform performance analysis such as life prediction;

Conventional thickness gauges only use one thickness measurement technology: for example, the traditional piezoelectric ultrasonic thickness measurement technology requires coupling agent, which is easy to cause environmental pollution, and requires grinding and other operations, which affects the efficiency and limits the application field. The eddy current thickness measurement technology is affected by the skin effect, and it is difficult to detect the deeper information of the specimen. Due to the limitation of the excitation coil of the eddy current sensor, it is still insufficient for large-area wall thickness detection. The measurement methods of these thickness gauges are single, and the measurement results are not comparable, so the accuracy is difficult to quantify. Based on this, the present invention integrates the three technologies of ultrasound, eddy current and EMAT, and detects the test piece through the three methods, which increases the comparability of the measurement results, reduces the misjudgment rate when the single method is measured, and the measurement results The large deviation method realizes the active self-calibration (correction) function, realizes the sharing of resources and the complementary advantages of technologies, better avoids missed detection and false detection, and greatly improves the accuracy and reliability of thickness measurement sex. It is a more efficient, reliable and safe non-destructive thickness measurement method.

Description of drawings

Fig. 1 is a system block diagram of an embodiment of the present invention;

Fig. 2 is the flowchart of the self-verification algorithm of the embodiment of the present invention;

Fig. 3 is an explanatory flow diagram of an integrated non-destructive thickness measurement method of ultrasonic wave, eddy current and EMAT according to an embodiment of the present invention;

Fig. 4 is a schematic block diagram of ultrasonic thickness measurement according to an embodiment of the present invention;

Fig. 5 is a principle block diagram of eddy current thickness measurement according to an embodiment of the present invention;

Fig. 6 is a block diagram of the principle of EMAT thickness measurement according to the embodiment of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

As shown in Figure 1-6, it includes excitation module 1, receiving preprocessing module 2, analog switch 3, A/D converter 4, self-checking module 5, microcontroller MCU6, CPU module 7, power supply module 8, etc. . The excitation module 1 is connected to the receiving preprocessing module 2, the receiving preprocessing module 2 is connected to the analog switch 3, the analog switch 3 is connected to the A/D converter 4, and the A/D converter 4 is connected to the microcontroller MCU6, self-checking Module 5 is connected with microcontroller MCU6, microcontroller MCU6 is connected with CPU module 7, and CPU module 7 is connected with data storage module 9, display screen 10, communication interface 11, alarm module 12 and other peripheral modules. Among them, ultrasonic excitation module, eddy current excitation module and EMAT excitation module; receiving preprocessing module includes ultrasonic receiving preprocessing module, eddy current receiving preprocessing module and EMAT receiving preprocessing module; self-checking module includes self-checking circuit and calibrator .

As shown in Figure 3, a kind of ultrasonic, eddy current and EMAT integrated nondestructive thickness measurement method, its method comprises the following steps: Step A), select a mode to be detected in three kinds of nondestructive measurement modes of ultrasonic wave, eddy current and EMAT, Place the corresponding probe on the tested piece;

Step B), the signal generator is controlled by the microcontroller MCU to generate the excitation signal of the required specific frequency, and the transmitter end of the probe is excited after the power is amplified;

Step C), according to the respective excitation principles of ultrasonic wave, eddy current and EMAT, a voltage signal is induced at the receiving end of the probe, and the voltage signal is processed by the receiving preprocessing module to pick up the signal;

Step D), the analog signal obtained after processing is sent to the A/D converter through the analog switch to be converted into a digital signal, and the measured thickness value of the test piece is displayed and stored after being processed by the CPU module;

Step E), when the three methods of ultrasonic, eddy current and EMAT are used to measure the same test piece respectively, start the self-verification program, and compare the measurement results of the three non-destructive thickness measurement methods with each other through the self-verification module, Realize the active self-calibration function for methods with large deviations in measurement results.

In actual operation, the microcontroller MCU6 controls the signal generator to generate excitation signals of specific frequencies required for ultrasonic thickness measurement, eddy current thickness measurement, and EMAT thickness measurement—square wave, sine wave and pulse signal, which are amplified by power and then excited The probe coil sends the signal received by the probe coil into the corresponding detection channel, so that the signal is loaded on the corresponding ultrasonic, eddy current, and EMAT sensors, so that each sensor completes the pickup of the signal containing information about the thickness of the tested specimen. After the information is picked up, it is sent to the receiving preprocessing module of ultrasonic, eddy current, and EMAT to process the picked up signal, and the analog signal obtained after processing is sent to the A/D converter 4 through the analog switch, and the analog signal representing the thickness of the test piece is converted to It is a digital signal, and the measurement data is sent to the CPU module 7 according to the CPU requirement. The CPU module 7 displays and stores the measured thickness value of the test piece on the display, and compares it with the threshold value, and starts the alarm unit if it exceeds the range. Whenever the same test piece is measured by the three methods of ultrasonic, eddy current and EMAT, the self-calibration program is started, and the three measurement data are sent to the self-calibration circuit for calibration. At the same time, the calibrator performs self-calibration The output value of the circuit is compared and judged in pairs. If the three measurement data are within the error range, no processing will be performed; if a certain measurement data has a large deviation, the calibrator will give an error indication and send it to the microcontroller MCU6 to calibrate the error channel. deal with. The error indication, error channel and calibration completion command generated during the self-checking process are synchronously sent to the CPU module 7 and displayed on the display to notify the user. The measurement results can be transmitted to the computer for storage through the USB interface, so as to realize the operation of the ultrasonic, eddy current, and EMAT integrated non-destructive thickness gauge.

Further, as shown in FIG. 4 , the ultrasonic excitation module is composed of a signal generator, a drive circuit, a high-voltage switch circuit, and an ultrasonic sensor (also called an ultrasonic transducer). In actual work, the microcontroller MCU6 provides a low-voltage adjustable pulse width signal to generate a square wave pulse signal for the signal generator. Since the signal power is small and the voltage amplitude is low, it needs to be amplified by the drive circuit to drive the excitation transducer Ultrasonic waves are generated, and then converted into high-voltage narrow-pulse excitation signals by a high-voltage switch circuit, and the resulting high-voltage narrow-pulse excitation signals are applied to the transducer to generate ultrasonic waves.

Further, as shown in FIG. 4 , the ultrasonic signal receiving preprocessing module is composed of a preamplifier circuit, a bandpass filter circuit, and a program-controlled automatic gain circuit. Send the signal to the preamplifier circuit for signal amplification, and suppress other noise and interference to achieve the maximum signal-to-noise ratio. The pre-amplified signal passes through a band-pass filter for frequency selection processing to select frequencies near the excitation frequency and filter out interference noise. Then the filtered signal is sent to the program-controlled gain amplifier, and the signal is adjusted according to time to keep the amplitude of the amplified signal at the same order of magnitude, and at the same time meet the level requirements of the data acquisition circuit. The output signal is sent to the A/D converter 4 for high-speed acquisition, and then sent to the microcontroller MCU for digital operation processing, and then the obtained thickness value is sent to the CPU module 7 according to the CPU demand, and the measured thickness value is displayed and stored.

Further, as shown in FIG. 5 , the eddy current signal excitation module is composed of a signal generator, a power amplifier, and an eddy current sensor. The microcontroller MCU6 controls the signal generator to generate a sine wave excitation signal, which is fed back to the probe coil through the power amplifier, and the signal of the probe measurement coil is amplified to obtain a measurement signal.

Further, as shown in FIG. 5 , the eddy current signal receiving preprocessing module is composed of a detection circuit, a balanced filter and an adjustable gain amplification circuit. In actual work, the measurement signal obtained by the eddy current excitation unit is sent to the detector to detect the DC signal. After the DC signal is filtered by the balance filter to filter the interference noise, it is sent to the adjustable gain amplifier circuit for zero adjustment and amplification. The amplified DC signal is sent to To the A/D converter 4, the A/D converter 4 performs high-speed sampling on the incoming analog signal, sends the converted digital signal to the microcontroller MCU6 for digital filtering processing, nonlinear correction and compensation, and then converts the Relevant data is sent to CPU module 7, and the measured thickness value is displayed and stored.

Further, as shown in FIG. 6 , the EMAT excitation module is composed of a signal generator, a driving circuit, a class D power amplifier circuit, a matching circuit, and an electromagnetic acoustic transducer EMAT. In actual work, under the control of the microcontroller MCU6, the signal generator generates a narrow pulse signal. Since the signal power is very small and the voltage amplitude is low, it needs to be amplified by the drive circuit, and then sent to the class D power amplifier circuit to amplify a single modulation pulse. , the formed high-voltage narrow-pulse excitation signal has greater power and higher frequency characteristics, and then sent to the matching circuit to improve the energy transmission efficiency of the circuit, and at the same time protect the transmission circuit according to EMAT. According to the principle of electro-magnetism-acoustic conversion, the high-voltage narrow-pulse excitation signal passed through the matching circuit excites EMAT to generate electromagnetic ultrasonic waves in the test piece.

Further, as shown in FIG. 6 , the EMAT signal receiving preprocessing module is composed of a matching circuit, a preamplifier circuit, a band-pass filter circuit, and a program-controlled automatic gain circuit. The echo signal is impedance-matched through the matching circuit to improve the receiving conversion efficiency. Due to the low transduction efficiency of EMAT, the echo signal received from the matching circuit is very weak, and there is a large noise interference in the signal, so the received The echo signal is sent to the preamplifier circuit for signal amplification processing, and suppresses noise interference to achieve the maximum signal-to-noise ratio. The pre-amplified signal passes through a band-pass filter for frequency selection processing to select the echo signal in the effective frequency band and filter the interference noise. Due to the different lengths of the ultrasonic channels and the inconsistencies in the thickness of the pipes, the amplitude of the echo signal is also different in each measurement. It is necessary to send the filtered signal to the programmable gain amplifier to adjust the gain of the echo signal at different times. , so that the amplitude of the amplified signal remains at the same order of magnitude. Then the output signal is sent to the A/D converter 4 for high-speed acquisition, and then sent to the microcontroller MCU for digital operation processing, and then the relevant data is sent to the CPU module 7 in response to the CPU demand, and the measured thickness value is displayed and stored.

Further, the communication response between the microcontroller MCU6 and the CPU module 7 is in charge of a special communication logic circuit. The CPU module 7 is responsible for the display of measurement results, over-limit alarm, data storage, communication with the background control terminal, and power supply voltage monitoring. The power supply module 8 is responsible for power management. On the one hand, it provides the required power supply voltage for each part of the system, and on the other hand, it detects the battery voltage, temperature, access of external power supply and battery charging. Simultaneously, the invention realizes real-time online detection, and real-time monitoring of the health status of the specimen can be realized through the USB interface. The measurement results can be transmitted to the background control terminal computer for storage through the USB interface, so as to realize the operation of the ultrasonic, eddy current and EMAT integrated non-destructive thickness gauge to analyze the performance of the test piece, improve its production process and process, and improve product quality.

The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (8)

1. a ultrasound wave, the integrated nondestructive thickness measuring instrument of eddy current and EMAT, it is characterized in that: it comprises stimulating module, receive pretreatment module, analog switch, A/D converter, the self checking module, microcontroller, the CPU module, supply module, the peripheral demonstration storage of CPU, described stimulating module is connected with the reception pretreatment module, described reception pretreatment module is connected with analog switch, described analog switch is connected with A/D converter, described A/D converter is connected with microcontroller, described self checking module is connected with microcontroller, described microcontroller is connected with the CPU module, described CPU module respectively with display screen, communication interface, alarm module, data memory module connects, described stimulating module comprises the ultrasonic exciting module, eddy current stimulating module and EMAT stimulating module, described reception pretreatment module comprises that ultrasound wave receives pretreatment module, eddy current receives pretreatment module and EMAT receives pretreatment module.

2. ultrasound wave according to claim 1, the integrated nondestructive thickness measuring instrument of eddy current and EMAT, it is characterized in that: described ultrasonic exciting module is by signal generator, driving circuit, high voltage switch circuit, ultrasonic sensor forms, described ultrasonic signal receives pretreatment module by pre-amplification circuit, bandwidth-limited circuit, the program controlled automatic gain circuitry forms, described signal generator is connected with driving circuit, described driving circuit is connected with high voltage switch circuit, described high voltage switch circuit is connected with ultrasonic sensor, described ultrasonic sensor is connected with pre-amplification circuit, described pre-amplification circuit is connected with bandwidth-limited circuit, described bandwidth-limited circuit is connected with the program controlled automatic gain circuitry.

3. ultrasound wave according to claim 1, the integrated nondestructive thickness measuring instrument of eddy current and EMAT, it is characterized in that: described eddy current stimulating module is by signal generator, power amplifier, eddy current sensor forms, eddy current signal receives pretreatment module by detecting circuit, balance filtering circuit and adjustable gain amplifying circuit form, described signal generator is connected with power amplifier, described power amplifier is connected with eddy current sensor, described eddy current sensor is connected with detecting circuit, described detecting circuit is connected with the balance filtering circuit, described balance filtering circuit is connected with the adjustable gain amplifying circuit.

4. ultrasound wave according to claim 1, the integrated nondestructive thickness measuring instrument of eddy current and EMAT, it is characterized in that: described EMAT stimulating module is by signal generator, driving circuit, D class power amplification circuit, match circuit, EMAT EMAT forms, described EMAT signal receives pretreatment module by match circuit, pre-amplification circuit, bandwidth-limited circuit, the program controlled automatic gain circuitry forms, described signal generator is connected with driving circuit, described driving circuit is connected with D class power amplification circuit, described D class power amplification circuit is connected with match circuit, described match circuit is connected with EMAT EMAT, described EMAT EMAT is connected with match circuit, described match circuit is connected with pre-amplification circuit, described pre-amplification circuit is connected with bandwidth-limited circuit, described bandwidth-limited circuit is connected with the program controlled automatic gain circuitry.

5. the integrated nondestructive thickness measuring instrument of ultrasound wave according to claim 2, eddy current and EMAT, it is characterized in that: described ultrasonic sensor is arranged in ultrasonic probe, described ultrasonic probe is transmitting-receiving integrated, ultrasonic sensor consists of bimorph, a wafer is for launching ultrasound wave, and another wafer is for accepting ultrasound wave.

6. the integrated nondestructive thickness measuring instrument of ultrasound wave according to claim 3, eddy current and EMAT, it is characterized in that: described eddy current sensor is arranged in eddy current probe, described eddy current probe is transmitting-receiving integrated, the outside of eddy current sensor all adopts shielding structure, eddy current sensor consists of two groups of coil winding, one group of coil winding is the transmitting coil winding, another group is the receiving coil winding, the input end of described transmitting coil winding is connected with the output of stimulating module, and described receiving coil winding is connected with the input of accepting pretreatment module.

7. the integrated nondestructive thickness measuring instrument of ultrasound wave according to claim 4, eddy current and EMAT, it is characterized in that: described EMAT EMAT is arranged in the EMAT probe, described EMAT probe is for transmitting-receiving integrated, the outside of EMAT EMAT all adopts shielding structure, EMAT EMAT consists of two groups of coil winding, one group of coil winding is the transmitting coil winding, another group is the receiving coil winding, the input end of described transmitting coil winding is connected with the output of stimulating module, and described receiving coil winding is connected with the input of accepting pretreatment module.

8. the integrated nondestructive thickness measuring method of ultrasound wave, eddy current and EMAT, it is characterized in that: its method comprises the following steps:

Steps A), select a kind of pattern that will detect in ultrasound wave, eddy current and tri-kinds of nondestructive measurement patterns of EMAT, the correspondence probe is placed on test specimen;

Step B), produce the pumping signal of required characteristic frequency, incentive probe transmitting terminal after power amplification by microcontroller control signal generator;

Step C), according to ultrasound wave, eddy current and EMAT exiting principle separately, induce voltage signal at the probe receiving end, voltage signal carries out the processing of pickoff signals through receiving pretreatment module;

Step D), the simulating signal obtained after processing sent into to A/D converter through analog switch be converted to digital signal, after processing by the CPU module arithmetic, the specimen thickness value of measuring is shown and stores;

Step e), when adopting respectively ultrasound wave, eddy current, tri-kinds of methods of EMAT all to measure to same test specimen, start self check program, by the self checking module, the measurement result of three kinds of nondestructive thickness measuring methods is compared separately from each other, realized the active self checking function to the larger method of measurement result deviation.

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