Automatic Exposure Controls/Phototimers are designed to maintain consist film density regardless of breast thickness or composition. This consistency needs to be evaluated on a routine basis as a regular quality control procedure. The Phototimer Consistency Test Tool consists of seven (7) pieces of acrylic (RMI 159A) or six (6) pieces of Tissue Equivalent Breast Material (RMI 159A-BR). With this test tool different thicknesses can be imaged and densities measured to confirm that the automatic exposure control/phototimer is operating at its optimum level.