Detection of sub-surface defects in ferromagnetic steels using a pulsed eddy current technique

2018 ◽  
Vol 60 (6) ◽  
pp. 311-316 ◽  
Author(s):  
T Azizzadeh ◽  
M S Safizadeh
Keyword(s):  
Eddy Current ◽  
Surface Defects ◽  
Pulsed Eddy Current ◽  
Current Technique ◽  
Ferromagnetic Steels

Thickness Evaluation of Aluminium Plate Using Pulsed Eddy Current Technique

2013 ◽  
Vol 94 (2) ◽  
pp. 89-93 ◽  
Author(s):  
Gurpartap Singh ◽  
Harsh Madhukar Bapat ◽  
Bhanu Pratap Singh ◽  
Manojit Bandyopadhyay ◽  
Rakesh Kumar Puri ◽  
...  
Keyword(s):  
Eddy Current ◽  
Pulsed Eddy Current ◽  
Current Technique ◽  
Thickness Evaluation

scholarly journals Lift-off Invariant Inductance of Steels in Multi-Frequency Eddy-Current Testing

2021 ◽  
Author(s):  
Mingyang Lu ◽  
Xiaobai Meng ◽  
Ruochen Huang ◽  
Liming Chen ◽  
Anthony Peyton ◽  
...  
Keyword(s):  
Eddy Current ◽  
High Accuracy ◽  
Eddy Current Testing ◽  
Current Testing ◽  
Pulsed Eddy Current ◽  
Working Frequency ◽  
Lift Off ◽  
Ferromagnetic Steels ◽  
Point Of Intersection ◽  
Steel Properties

Eddy current testing can be used to interrogate steels but it is hampered by the lift-off distance of the sensor. Previously, the lift-off point of intersection (LOI) feature has been found for the pulsed eddy current (PEC) testing. In this paper, a lift-off invariant inductance (LII) feature is proposed for the multi-frequency eddy current (MEC) testing, which merely targets the ferromagnetic steels. That is, at a certain working frequency, the measured inductance signal is found nearly immune to the lift-off distance of the sensor. Such working frequency and inductance are termed as the lift-off invariant frequency (LIF) and LII. Through simulations and experimental measurements of different steels under the multi-frequency manner, the LII has been verified to be merely related to the sensor parameters and independent of different steels. By referring to the LIF of the test piece and using an iterative inverse solver, one of the steel properties (either the electrical conductivity or magnetic permeability) can be reconstructed with a high accuracy.

Sign in / Sign up

Export Citation Format

Share Document