J Med Phys Close
 

Figure 1: The cylindrical test tool to provide a constant depth of 5 cm for an FC65 ion chamber. Three angulations of the gantry can be checked with this tool routinely. Under-table gantry position cannot be measured as the mounting block comes in the path of the beam

Figure 1: The cylindrical test tool to provide a constant depth of 5 cm for an FC65 ion chamber. Three angulations of the gantry can be checked with this tool routinely. Under-table gantry position cannot be measured as the mounting block comes in the path of the beam