Phase Angle Evaluation
Phase angle evaluation measures the angle between excitation signal and sensor signal in an eddy current method. It helps in flaw detection and characterization of material properties.
Physical-Chemical Mechanism of Action
Phase angle evaluation is based on measuring the phase difference between the excitation signal (e.g., an electric or magnetic field) and the sensor signal generated by a material in an eddy current method. This phase difference is a measure of material constants such as reluctance or permeability angle.
Metallurgical Relevance & Welding Risks
Phase angle evaluation can be used to detect various defects in the weld, such as porosity, cracks, or uneven weld thickness. It also provides information on material properties like hardness and strength, which is crucial for selecting the right welding process.
Workshop Practice & Instructions
To perform accurate phase angle evaluation, the excitation and sensor signals must be correctly recorded. The measurement should be done in a calibrated eddy current setup with controlled temperature and voltage. The phase angles should then be evaluated digitally to identify defects or material properties.