What are the three basic ultrasonic inspection methods?
There are three main types of ultrasonic testing methods:
- Through transmission. Through transmission employs two transducers, each placed on opposite sides of the material being tested.
- Pulse echo. Pulse echo is more sensitive than through transmission.
What is ultrasonic testing PDF?
Ultrasonic Testing (UT) uses high frequency sound waves (typically in the range between 0.5 and 15 MHz) to conduct examinations and make measurements.
What is the basic principle of ultrasonic testing?
The basic principles of ultrasonic testing involve the propagation and reflection of sound waves. This 8-minute, 14-second video shows how defects and abnormalities can be detected using the pulse-echo method.
What materials can ultrasonic testing be used on?
In industrial applications, ultrasonic testing is widely used on metals, plastics, composites, and ceramics. The only common engineering materials that are not suitable for ultrasonic testing with conventional equipment are wood and paper products.
What are the advantages of ultrasonic testing?
Advantages of ultrasonic inspection as a method of Non-Destructive Examination are:
- Internal defects can be detected and sized when a validated procedure is applied.
- Thick specimens take no more time to examine than thin ones, assuming correct instrumentation set up.
- Access to only one side of the component is needed.
How sensitive is ultrasonic testing?
Sensitivity is the ability of an ultrasonic inspection system to detect a very small discontinuity is generally increased by using relatively high frequencies (short wavelengths). The sensitivity of the ultrasonic test system depends on search unit, pulser, and amplifier characteristics.
Is ultrasonic testing easy to use?
Companies leverage ultrasonic technology for their volumetric nondestructive testing (NDT) needs. The most advanced ultrasonic equipment is durable, often portable, accurate, and incredibly easy to use.
Is code for ultrasonic testing?
For general technique relating to ultrasonic testing, reference may be made to IS 3664:1981 ‘Code of practice for ultrasonic pulse echo testing by contact and immersion methods @st revision). This standard gives detailed procedure of examination of butt welds in ferritic steel.
How accurate is ultrasonic testing?
Under optimum conditions, commercial ultrasonic gages can achieve a level of accuracy as high as ±0.001 mm (0.00004 in.) and ±0.025 mm (0.001 in.) or higher in most common engineering materials.
What is critical angle in ultrasonic testing?
A critical angle is an angle of incidence at an interface between two dissimilar materials beyond which a new mode appears in the refracted beam and the existing one vanishes. Example: for Perspex on steel: angle of incidence 27-1/2 ° compressional wave mode vanishes and is replaced by shear wave.
What are limitations of ultrasonic testing?
Disadvantages of Ultrasonic Testing Techniques:
- Training is more extensive than other methods.
- More expensive than other methods.
- Difficult to use on thin materials.
- Part Geometry can cause complications.
- Needs relatively smooth surface to couple transducer.
What is the frequency range for ultrasonic test?
400 kHz to 25 MHz
Most ultrasonic testing is available within 400 kHz to 25 MHz. These vibrations are beyond the audible range and propagate in the test material as waves of particle vibrations. Sound beams of all frequencies can penetrate fine-grained material without difficulty.
What is frequency in ultrasonic testing?
Most ultrasonic testing is performed at frequencies between 1 MHz and 10 MHz, however commercially available transducers range in frequency from less than 50 KHz to greater than 200 MHz.