Ultrasonic Testing (UT)
Ultrasonic methods of non destructive testing use beams of mechanical waves of short wavelength and high frequency, transmitted from a probe and detected by the same or other probes.
Usually, pulsed beams of ultrasound are used and in the simplest instruments a single probe, hand held, is placed on the components surface. An oscilloscope display with a time base shows the time it takes for a ultrasonic pulse to travel to a reflector (a flaw, the back surface or other free surface) in terms of distance travelled across the oscilloscope screen.
The height of the reflected pulse is related pulse is related to the flaw size as seen from the transmitter probe. The relationship of flaw size, distance and reflectivity are complex, and a considerable skill is required to interpret the display.
Ultrasonic examination has been utilised as a non-destructive testing method to carry out a wide variety of testing tasks enabling the equipment to conduct internal examination and make measurements of a component.
It is also a commonly accepted method of checking the wall thickness of pipelines, tanks, silos and vessels, which are suspected of being eroded internally or where access is restricted to one side of the material.
Ultrasonic testing equipment is small, lightweight, portable and presents no safety hazards, therefore it is ideal for carrying out examination of raw materials, components, welds etc.., together with corrosion monitoring and thickness measurements on components in service.
Independent Integrity Inspection Limited (INDEi) offer a range of ultrasonic testing services including thickness surveys, weld examination, forging and casting component inspections, condition monitoring and critical defect sizing.