The Flaw Detection Work of the Testing Machine is Reflected from Multiple Angles

The Flaw Detection Work of the Testing Machine is Reflected from Multiple Angles

1. How does the eddy current testing machine judge whether the tested object is abnormal?


There are many aspects involved in the working process of the eddy current testing equipment, including the generation, reception, signal conversion and processing of ultrasonic waves. The method of generating ultrasound is to generate an excitation signal through a circuit and transmit it to a crystal with piezoelectric effect (such as quartz, lithium sulfate, etc.) to vibrate to generate ultrasound.


When receiving the reflected ultrasonic wave, the piezoelectric crystal will be subjected to the pressure of the reflected sound wave to generate an electrical signal, which is sent to the signal processing circuit for a series of processing, and the eddy current testing machine finally forms an image for people to observe and judge.


The probe used in the eddy current inspection equipment is a coil made of copper wire. The coil shape can be changed to better suit specific applications.


1) At the selected frequency, the alternating current passing through the coil generates a magnetic field around the coil.


2) When the coil is close to the conductive material, an eddy current is induced in the material.


3) If the defect in the conductive material interferes with the flow of eddy current, the magnetic coupling effect of the probe will change. By measuring the impedance change of the coil, the defect signal can be interpreted.


2. The fuselage structure of the eddy current testing machine is sturdy and durable, which can withstand harsh testing environments.


Now, there are thousands of instruments in use all over the world. This instrument is small, lightweight, and uses two lithium-ion batteries for power. When the battery is fully charged, it can perform manual or semi-automatic detection for up to 6 hours. The display screen of the eddy current testing machine can display high-definition color images in real time.


In most light conditions, the operator can observe the defects and the subtle conditions of the material. The user can use the jog dial and function keys to easily browse the simple and intuitive interface of the instrument. You can also connect a USB mouse to the eddy current testing machine to conveniently perform detection and analysis with the help of the mouse.


Eddy current testing (ECT) technology is based on the following working principle of magnetic coupling: the probe sensor (coil) close to the measured workpiece (ferromagnetic or non-ferromagnetic conductive material) generates eddy current in the measured workpiece, and the signal is displayed in the impedance diagram of the eddy current testing machine. When using eddy current technology, as long as the distance between the probe and the metal is kept within a reasonable close range, generally 0.5 mm to 2.0 mm, defects in the material can be detected through a thin coating (such as a paint layer).


Since the eddy current array and ECT technology are based on the same basic principles (and physics theory), the eddy current array technology can also be tested through the paint layer. In addition, it can also provide the advantages of the eddy current array (ECA) technology including the functions such as large coverage, fast scanning speed, high detection probability and color imaging.