AN INFRARED MEASURING APPARATUS AND METHOD FOR ON-LINE APPLICATION IN MANUFACTURING PROCESSES

摘要

A single vane (46, 48) shutter flag (38) is asynchronously controlled (82) s o that a measuring system light source (22) is interrupted for a minimum necessary amount of time for standardization/calibration and normalization o f InGaAs system detectors (68a - 68d). Source/detector hemispheres (50, 62) or serially connected randomly oriented fiber bundles (132) homogenize light passing to the detectors. Light source testing is performed by measuring spectral power distributions at a plurality of light source power levels and comparing the measurements to baseline characteristics established for the light source. Calibration sample life is extended indefinitely by controllin g the shutter flag to block source light except for short calibration time periods during which standard light levels are provided.