Infrared pyrometers in service on a Claus thermal reactor are in an extreme environment. It is possible for the pyrometer to read incorrect values for a number of reasons including miscalibration or misalignment. Miscalibration can be caused by slight drift of the electronics among other factors. If the accuracy of the unit is in question, action must first be taken to verify that the optical sight path is not occluded by the build-up of material and that the lens of the pyrometer is not obscured. Subsequently, the optical alignment of the pyrometer must be verified to be concentric with the bore. The pyrometer can become misaligned due to severe vibration, improper installation or mishandling. Once actions have been taken to verify the alignment and optical sight path, the calibration of the unit must be verified. A number of options exist for pyrometer verification and calibration including both in place calibration and uninstalled calibration, each with both advantages and drawbacks.
展开▼
