The embodiments described herein generally relate to methods of noise compensation for proper temperature detection in thermal processing chambers and devices for achieving the same. Methods can include determining noise produced by a lamp zone and extrapolating the noise from the detected photocurrent. Devices can include a processing chamber, a substrate support disposed in the processing chamber, the substrate support having a high thermal mass, a pyrometer below the substrate support and oriented to view radiation emitted by the substrate and a controller configured to subtract a time invariant noise component and a time variant noise component from the pyrometer signal.