Differences between Ultrasonic Flaw Detector and Eddy Current Testing Machine

1. Different principles

The ultrasonic flaw detector theory is to use ultrasonic energy to penetrate into the depth of the metal material, and when the ultrasonic energy enters from one section to another section, the reflection occurs at the edge of the interface to check the defects of parts. When the ultrasonic beam passes from the surface of the part to the metal from the probe, the reflection wave will occur respectively when it meets the defect and the bottom of the part, the pulse waveform will be formed on the fluorescent screen, and the root will be detected according to these pulse waveforms, then the position and size of defects can be determined.

Eddy current testing machine: It uses the magnetic coil to generate the eddy current in the conductive component and measures the change of eddy current by the detecting coil, so as to obtain relevant information on component defects.

2. Different uses

An ultrasonic flaw detector machine can be used in both laboratory and field engineering. The digital ultrasonic flaw detector can detect, locate, evaluate and diagnose various defects in metal and non-metal materials quickly, conveniently, noninductively and accurately, such as pores, sand holes, inclusions, folds, cracks, incomplete fusion and incomplete penetration of welds in metal materials. At the same time, it has the outer circumference detect functions to detect axial workpieces, cylindrical workpieces, seamless steel pipes, straight welded pipes and other parts. Ultrasonic flaw detectors are widely used in the manufacturing, production and quality control links of scientific research, electric power, petrifaction, metallurgy, casting, automobile, machinery, industry, steel structure, boilers, pipelines, pressure vessels, railway transportation and many other fields, which has received customer's praise and achieved good economic and social benefits.

Eddy current flaw detector: It is only applicable to conductive materials and can only detect surface or near-surface layer defects. It is not suitable for components with complex shapes. It is mainly used to detect condenser tubes, turbine blades, central holes and welds of turbine rotors in thermal power plants.