Non-Destructive Testing (NDT) Study Guide & Core Inspection Methods Revision
Notes
What is radiography - ✔✔This is where x rays are passed through metal and other materials to
produce a record of the material. Used mainly on welded joints. Detects surface and below.
What is NDT used for? - ✔✔To detect flaws within the object without damaging it
What is a simple method of NDT? Explain. - ✔✔Visual inspection. Good lighting is important
and magnification is used to see tiny surface flaws.
What is penetrant dye testing? - ✔✔Coloured dye is carried by a penetrant that is fluorescent.
This soaks into cracks so when the excess is wiped away, it can be easily spotted in cracks using
UV light. Used on aluminium castings.
Magnetic Particle test - ✔✔Used to detect surface flaws and close to surface flaws. Dry or wet
particles are applied to a magnetised component. The Particles show the magnetic field and any
distortions show flaws. Used in vehicle manufacturing.
Ultrasonic testing - ✔✔This test uses a machine to create a high frequency sound vibration. A
probe is passed over the material which sends out this sound. They are reflected back to the
probe when they hit the bottom of the piece. If there is are flaw the vibrations will return
quicker. It is ideal for forgings or castings.
Eddy current test - ✔✔Used on conductive metals. An induction coil is fed with AC current and
creates an eddy current in the work. The currents are distorted by flaws and is detected by an
oscilloscope.
Notes
What is radiography - ✔✔This is where x rays are passed through metal and other materials to
produce a record of the material. Used mainly on welded joints. Detects surface and below.
What is NDT used for? - ✔✔To detect flaws within the object without damaging it
What is a simple method of NDT? Explain. - ✔✔Visual inspection. Good lighting is important
and magnification is used to see tiny surface flaws.
What is penetrant dye testing? - ✔✔Coloured dye is carried by a penetrant that is fluorescent.
This soaks into cracks so when the excess is wiped away, it can be easily spotted in cracks using
UV light. Used on aluminium castings.
Magnetic Particle test - ✔✔Used to detect surface flaws and close to surface flaws. Dry or wet
particles are applied to a magnetised component. The Particles show the magnetic field and any
distortions show flaws. Used in vehicle manufacturing.
Ultrasonic testing - ✔✔This test uses a machine to create a high frequency sound vibration. A
probe is passed over the material which sends out this sound. They are reflected back to the
probe when they hit the bottom of the piece. If there is are flaw the vibrations will return
quicker. It is ideal for forgings or castings.
Eddy current test - ✔✔Used on conductive metals. An induction coil is fed with AC current and
creates an eddy current in the work. The currents are distorted by flaws and is detected by an
oscilloscope.
