Question: what are the ndt methods?
Answer: Acoustic Emission Testing (AE) ... 
Electromagnetic Testing (ET) ... 
Ground Penetrating Radar (GPR) ... 
Laser Testing Methods (LM) ... 
Leak Testing (LT) ... 
Magnetic Flux Leakage (MFL) ... 
Microwave Testing. ... 
Liquid Penetrant Testing (PT)