A system and method for thermally calibrating semiconductor process chambers is disclosed. In various embodiments, a first non-contact temperature sensor can be calibrated to obtain a first reading with the semiconductor process chamber. The first reading can be representative of a first temperature at a first location. The first non-contact temperature sensor can be used to obtain a second reading representative of a second temperature of an external thermal radiation source. The second temperature of the external thermal radiation source can be adjusted to a first temperature setting of the external radiation source such that the second reading substantially matches the first reading. Additional non-contact temperature sensor(s) can be directed at the external thermal radiation source and can be adjusted such that the reading(s) of the additional non-contact sensors are calibrated and matched to one another.