Densities & thicknesses of films of five different layer systems were determined in a grazing incidence X-ray analysis (GIXA) Round Robin test carried out by 3 industrial laboratories. The influence of both the experimental setup & the simulations software on these results is compared for the identical set of samples. Two approaches are adopted; firstly each laboratory measuring & simulating its own data and; each laboratory simulating the data that had been measured by another laboratory. The measured data from the 3 laboratories are analysed & reasons proposed to explain the relatively minor differences between them. Comparisons are also made between the simulations produced from the two approaches to determine variations & any systematic bias between the three laboratories. Overall, good agreement in film densities & thickness is is found.
