ULTRASONIC THICKNESS TESTING (UTT)
Ultrasonic Thickness Mesurements make part of the volumetric group of methods due to the use of the ultrasonic wave properties, although in fact they give the image of the element surface condition to the same extent as the surface methods.The thickness gauge calculates the element’s thickness at the point of measurement taking by measuring the time of ultrasonic lengthwise wave passage through the tested object. Owing to such properties it is possible to determine the actual thickness of a structure, which is vital for the assessment of the condition of many structures in operation, especially those which are strongly exposed to corrosion i.e. pipelines, tanks, etc. The thickness measurements, also referred to as measurements of corrosion losses, have become a common method for the shipping industry and form the basis for the Classification Societies (e.g. PRS, GL, LRS, BV, ABS, DNV, NKK) to approve the vessels to service.The modern thickness gauges provide very accurate measurements without the necessity of removing the paint coats, which significantly reduce the testing expenses being very convenient at the same time.