Figure 2. (a) Lateral view of measurement set-up. The chambers 0.6 cm³ and 0.1 cm³ are placed at positions A and B, respectively. The source position c is for the 0.6 cm³ and c' for the 0.1 cm³ chamber that means the heights of the effective points of chambers differed by 1.4 cm. (b) The offsets in positioning of the centre of chamber () and source (). The total offset in the setup distance is given by = –+.