An apparatus, a system and a method are disclosed. An exemplary apparatus includes a wafer processing chamber. The apparatus further includes radiant heating elements disposed in different zones and operable to heat different portions of a wafer located within the wafer processing chamber. The apparatus further includes sensors disposed outside the wafer processing chamber and operable to monitor energy from the radiant heating elements disposed in the different zones. The apparatus further includes a computer configured to utilize the sensors to characterize the radiant heating elements disposed in the different zones and to provide a calibration for the radiant heating elements disposed in the different zones such that a substantially uniform temperature profile is maintained across a surface of the wafer.