Amplitude-wavelength maps for X-ray computed tomography systems

Abstract Amplitude–wavelength (AW) maps or “Stedman diagrams” are often used to provide a graphical representation of the limitations and capabilities of surface measuring instruments. This paper presents an approach for setting the parameter constraints of X-ray computed tomography (CT) in terms of resolution and measuring range for the purpose of representing the performance of industrial CT systems on an AW map. Such AW map will allow instrument users to quickly compare the CT instrument performance to other measuring systems. Examples of the construction of AW maps for different working capabilities of X-ray CT systems, and based on experimental data, are provided. Polypropylene, aluminum, and steel are three workpiece materials considered for determining some of the limitations of measuring capability for the maps developed in this paper. Although the limiting boundaries of the AW plots presented in this paper set a generalized measure of performance for comparisons with other measuring instruments, they may evolve with more comprehensive models of the limiting factors in X-ray CT.