UT - Ultrasonic Inspection

Ultrasonic inspection (UT) is one of the most widely used methods of nondestructive inspection. Its primary application in the inspection of metals in the detection and characterization of internal flaws; it is also used to detect surface flaws, to define bond characteristics, to measure the thickness and extent of corrosion.

Beams of high frequency sound waves are introduced into materials for the detection of surface and subsurface flaws in the materials. The sound waves travel through the material with some attendant loss of energy (attenuation) and are reflected at interfaces.

The reflected beam is displayed and then analyzed to define the presence and location of flaws or discontinuities.

Cracks, laminations, shrinkage, cavities, bursts, flakes, pores, disbonds, and other discontinuities that produce reflective interfaces can be easily detected.

Inclusions and other inhomogeneity can also be detected by causing partial reflection or scattering of the ultrasonic waves or by producing some other detectable effect on the ultrasonic waves.


  • Superior penetrating power which allows the detection of flaws deep in the part.
  • High sensitivity, permitting the detection of extremely small flaws
  • Greater accurancy in determining the position of internal flaws, estimating size, characterizing orientation, shape, and nature.
  • Only one surface need to be accessible.
  • Immediate interpretation, automation, rapid scanning, in-line production monitoring, and process control.
  • No effect on nearby personnel, equipment and material
  • Portability


  • Rough, irregular in shape, very small or thin parts are difficult to inspect.
  • Discontinuities that are present in a shallow lawyer immediately beneath the surface may not be detectable

    Ultrasonic thickness inspection on pressure vessels

    The integrity verification on pressure equipment is a combination of the results of a visual inspection conducted externally and, where possible, internally to the frame, supplemented by Ultrasonic thickness measurements.

    These non-destructive tests, aimed essentially at detecting surface discontinuities of the membrane produced by the combined action of mechanical and thermal stresses and the corrosive action generated by the contained fluid and the surrounding environment, for other explicitly prescribed (in Italy is the art. 12 of the D.M. n. 329/2004), are considered mandatory and preparatory to any other type of diagnostic verification for the purposes of integrity verification.

    Although elementary, the visual and spessimetric controls combine characteristics of effectiveness, speed and economy.

    The principles of thickness measurement for direct contact of metallic and non-metallic materials based on the detection of the flight time of ultrasonic pulses are defined in ISO16809: 2012 - "Non-Destructive Testing - Ultrasonic thickness measurement".



      The Img Ultrasonic Brick system allows the control of the storage tanks’ shell ring.

      The Brick is a magnetic motorized trolley with 4 independent motors, with a UT probe on board in continuous contact with the surface under examination.

      It is designed to follow the profile of flat surfaces.

      Combined with the UT-profiler software, it allows B-scan scanning of the ferrule in order to check the residual thickness.

        Electromagnetic-acoustic transduction (EMAT) at a vast range of surface temperatures, (-20 to +720 degrees Celsius)

        A convenient, compact, sophisticated and innovative field instrument, the EMAT Wall Thickness gauge NKD - 019E «UltraSonic» can be used to easily yet precisely measure the thickness of components, pipes, vessels and other metal objects.
        The gauge enables measurements to be taken at a vast range of surface temperatures, going from -20 to +720 degrees Celsius.

        As a rule, a plastic coatings, paint or limescale on the surface do not affect the results of measurements. The unique properties of this gauge are caused by the clever use of the principle of electromagnetic-acoustic transduction (EMAT), allowing ultrasonic waves to be generated and received by metal objects without direct contact or the use of couplant.

        In fact, the gap between the material being tested and the electromagnetic acoustic transducer in the gauge can be as high as 4mm!

        Areas of application:
        • Metalwork industry
        • Petrochemical industry
        • Aerospace industry
        • Construction of transport and machinery
        • Ship building and repair


        • Intuitive, easy-to-use interface
        • Able to measure objects with an extremely high surface temperature
        (up to 720 °С)
        • Able to transmit and receive ultrasound waves without the use of a
        couplant and at a distance of up to 4mm
        • Even units with insulation covers, corrosion or a rough surface can be
        tested non-destructively
        • Precise to 0,01mm
        • Wave speed automatically optimized to test object temperature
        • Measurements can be recorded for future analysis

          Phased array technology uses multiple ultrasonic elements and electronic time delays to create beams that can be steered, scanned, swept, and focused electronically for fast inspection, full data storage, and multiple angle inspections.

          Phased array technology provides precise measurement with the most reliable results.