Ultrasonic Testing for Procedure ISO 17640 & Acceptance Criteriya ISO 11666
Ultrasonic Testing method in which sound of high frequency( 1MHz and above), sound waves that are iinto the material being tested are used to detect discontinuity (planear or volumetric). The sound waves travel through the materials with some attenuation (due to absoption & scattering) of energy, sound are reflected at an interfaces. Amount of reflection sound receive by sencor depends on nature of discontinuity, size and orientation
The reflected beam is detected and analyzed to define the presence and location of flaws.
Ultrasonic waves are almost completely reflected at metal to air/gas interfaces. Partial reflection occurs at metal to liquid or metal solid interfaces, with the specific percentage of reflected energy depending on acustic impedance of two interface medium.
Ultrasonic inspection instruments detect flaws :
- Reflection of energy from metal-gas interfaces, metal-liquid interfaces or discontinuities within the metal itself.
- Time of transit of a sound wave through the test piece from the entrance point at the sending (transmitting) transducer to the exit point at the receiving transducer, and
- Attenuation of the beam of sound waves by absorption and scattering within the test piece.
- Ultrasonic Flaw detection requires by experienced technicians.
- Technical knowledge is required for the development of Ultrasonic testing procedures.
- Parts that are rough, irregular in shape, very small or thin or not homogenous are difficult to be teste
- Couplants are needed to provide effective transfer of ultrasonic wave energy between transducers and parts being tested.
- Reference standards are needed, both for calibrating the equipment and for characterizing flaws.
- Ultrasonic Equipments with built-in DGS curves, TGC, AWS flaw sizing techniques for weld inspections
- Transducers suitable for inspections, most sensitive, inspection applications
- T-K-Y joints testing