Principle of some NDT methods

"Conventional methods of Non-Destructive Test"

•Eddy current testing (ET)

“Localized electrical fields are induced into a conductive test specimen by electromagnetic induction”

•Thermal infrared testing (TIR)

“Temperature variations at the test surface measured/detected using thermal sensors/detectors instruments/cameras”

•Penetrant testing (PT)

“A liquid containing visible or fluorescence dye is applied to surface and enters discontinuities by capillary action”

•Visual testing (VT)

“Uses reflected or transmitted light from test object that is imaged with the human eye or other light-sensing device”

•Ultrasonic testing (UT)

“High-frequency sound pulses from a transducer propagate through the test material, reflecting at interfaces”

•Magnetic particle testing (MT)

“Test part is magnetized and fine ferromagnetic particles applied to surface, aligning at discontinuity”

•Radiographic testing (RT)

“Radiographic film is exposed when radiation passes through the test object. Discontinuities affect exposure”

•Acoustic emission testing (AE)

“As discontinuities propagate, energy is released and travels as stress waves through material. These are detected by means of sensors”

What’s next???

ECVT ???

Electrical Capacitance Volume Tomography (ECVT)

“ Based on permittivity distribution measurement”

MIT ???

Magnetic Inductance Tomography (MIT)

“Based on electrical conductivity measurement”

^{Reference :}

^{Hellier, Charles. Handbook of Nondestructive Evaluation. McGraw-Hill Companies, Inc : United States of America. 2003.}