Fig. 1

Dose-effect curves from participating laboratories. (a) Number of laboratories (y-axis) where the source used for the calibration curve was calibrated in terms of air kerma or absorbed dose to water. Colours indicate the radiation type used for the establishment of the calibration curves. (b & c) Manually and semi-automatically scored linear-quadratic dose-effect curves. The participants were labelled as L1-L14 and displayed by different colours and line types.