Surface Eddy Current Testing

Surface Eddy Current Testing is used for the detection of surface cracks in both nonferromagnetic and ferromagnetic materials. The method is very sensitive in detecting tight cracks. Calibration is performed on electrical discharge machined notches. In addition to detection, the method can accurately measure crack depth in nonferromagnetic materials. These materials include stainless steels and high temperature nickel chromium alloys. When sizing cracks, the eddy current test frequency is selected so that the depth of penetration is greater than the expected crack depth. Some common probes used for surface eddy current testing are spot probes, X-point probes and pencil probes.
Both surface eddy current testing and liquid penetrant testing are surface test techniques used for the detection of surface breaking cracks. Eddy current testing has advantages over liquid penetrant testing in certain applications:

• eddy current testing is significantly more sensitive than liquid penetrant testing in the detection of tight cracks (for example, stress corrosion cracks in stainless steels)
• eddy current testing can measure crack depth in nonferromagnetic materials, whereas liquid penetrant testing does not have this capability
• eddy current testing can test through paint coatings
• for testing in small areas, eddy current testing is much faster; liquid penetrant testing is slow because of the long dwell times.

From:(http://www.asnt.org/publications/materialseval/basics/nov03basics/nov03basics.htm)

NDT abbreviations

NDT abbreviations

NDT: Non Destructive testing.
ANDT: Advanced Non Destructive Testing.
PCN: Personnel Certification in Non-destructive testing.
ASNT: American Society for Non-Destructive Testing.
CWI: Certified Welding Inspector.
AWS: American Welding society.
NACE: National Association of Corrosion Engineers.
ASTM: American Society for Testing and Materials
RT: Radiographic testing.
UT: Ultrasonic Testing.
MT: Magnetic Testing.
PT: Penetrate testing.
ToFD: Time of Flight Diffraction.
ECT: Eddy Current Testing.
IRIS: Internal Rotary Inspection System.
VT: Visual Testing.
LT: Leak sealing.
HT: Hardness Testing.
MFL: Magnetic Flux Leakage.
PMI: Positive material identification.
RFT: Remote Field Testing
AE: Acoustic Emission


ASME: The American Society of Mechanical Engineers is a professional body, specifically an engineering society, focused on mechanical engineering

Above are not all NDT Abbreviations