Main advantages:
a. Strong penetrating ability, the detection depth can reach several meters;
b. High sensitivity, it can find reflectors with the same reflective ability as the air gap with a diameter of about several tenths of millimeters; the size of detectable defects can usually be considered to be one-half of the wavelength;
c. It is more accurate in determining the orientation, size, shape and so on of the internal reflector;
d. It is only necessary to approach the object to be inspected from one side;
e. Defect inspection results can be provided immediately;
f. The operation is safe and the equipment is portable.
Main disadvantages:
a. It should be operated carefully by experienced personnel;
b. It is difficult to inspect rough, irregularly shaped, small, thin or heterogeneous materials;
c. It is still difficult to accurately characterize and quantify the defects found;
d. Not suitable for structures with cavities.