The present invention concerns a method for measuring the thickness of any deposit of material on the inner wall of a structure conducting a fluid stream of hydrocarbons, the method comprising the steps of: applying a first heat pulse or continuous heating to at least one first section of the structure removing deposits on the inner wall of the first section of the structure; applying a second heat pulse to both the first section of the structure and at least one second section of the structure, the first and second sections being spaced apart, which heat pulse does not loosen any deposit of material in the second section; measuring the temperature of the wall of the structure or the fluid during the second heat pulse at both the first and second sections; and determining the thickness of any deposit of material on the inner wall of the structure at the second section based on the measured temperatures. The present invention also relates to a corresponding device and arrangement.