Ultrasonic thickness measurements (UTT, UTM) use longitudinal ultrasonic waves - the thickness of the element is calculated based on the wave transition time through the tested element. Only one-sided access to the test element is sufficient to carry out the measurement and it is not necessary to remove paint coating. Measurements can also be made using rope access, which makes it possible to measure in hard to reach areas. Using appropriate probes, the measurement can be made even on a hot element.
Ultrasonic thickness measurements, also referred to as corrosion loss measurements, are widely used in the industry. They are used both during manufacturing and operation. Measured objects are mainly elements which are susceptible to damage caused by corrosion, erosion or the action of chemicals, such as pipelines, tanks, ship hulls, buildings and many others.
Ultrasonic thickness measurements can be carried out on objects made of metals, plastics, glass, rubber, glass fibres, composite materials and others.
Ultrasonic thickness measurements have found widespread use in shipbuilding and are the main NDT method on the basis of which classification societies allow ships to move. Thickness measurements of hull components performed by Navitest are recognized by BV, DNV GL, LR and PRS.
With the traditional ultrasonic thickness measurement, information can be obtained about the actual wall thickness in measured point. Using Phased Array technique allows corrosion mapping of larger surfaces with a resolution of up to 1mm.