How many types of NDT are there?

There are six common methods of NDT (non-destructive testing) used in pipeline, oil and gas, mining, construction, tubing and equipment inspection. These frequently used types of NDT include radiography or x-ray testing (RT), eddy-current or electromagnetic testing (ET), magnetic particle testing (MT), dye penetrant inspection, visual testing and ultrasonic testing (UT). Ultrasonic testing may include methods such as phased array, time of flight diffraction, guided wave, etc. Each type of NDT has its own benefits and restrictions. In Alberta, inspection service providers most commonly use radiography testing. However, other types of NDT, such as phased array ultrasonic testing are becoming popular as well.