The ISO 32543-1 is the successor of EN 12543-2 and suitable for focal spots larger than 100µm. This standard is similar to ASTM E1165, please look here for the details. Compared to the other methods specified in the EN 12543 series and the ISO 32543 series, this method allows to obtain an image of the focal spot and to see the state of it (e.g. cratering of the anode).