Abstract: A method includes receiving first spectrograph data corresponding to a first material type, receiving second spectrograph data correspond to a second material type different than the first material type The method further includes generating first ratio data by comparing respective values of the first and second spectrograph data, generating a first drift value using the first ratio data, and performing one or more corrective actions based on a determination that the first drift value exceeds a first threshold.

Abstract: A device includes a calibration target attached to a chuck. The device also includes a camera fixed in a first position. The device also includes a reflectometer fixed in a second position. The device also includes one or more processing devices. The device also includes memory storing instructions that, when executed by the one or more processing devices, cause the device to move the chuck to a third position, capture an image using the camera, determine, using the image, a first actual position of the calibration target, determine a first offset value corresponding to a difference between a first expected position of the calibration target and the first actual position of the calibration target, and verify a calibration of the reflectometer using one or more of the first expected position of the calibration target or the first actual position of the calibration target.