What does the term "phase angle" represent in Eddy Current Testing?

The term "phase angle" in Eddy Current Testing represents the relationship between the resistive and inductive components of the eddy current signal. In this context, the phase angle is a crucial parameter because it indicates how the total impedance (the combination of resistance and reactance) behaves in relation to the current signal. Specifically, it reflects the phase difference between the voltage and current; this phase difference provides insights into the material properties, such as electrical conductivity and permeability.

When the phase angle is measured, it helps in differentiating between various materials and detecting flaws. A larger phase angle can correspond to higher reactance in the system, which can indicate specific material characteristics or changes in the measured surface. Understanding this relationship is vital for interpreting the data collected during eddy current testing, as it allows technicians to make informed assessments about the integrity of the components being tested.

The other options, while related to aspects of the eddy current signal, do not encapsulate the essence of what the phase angle specifically conveys regarding the impedance characteristics of the system.