Phosphor thermometry system

摘要

An apparatus for measuring the temperature of a moving substrate (20) includes an air gun (110) with a powder reservoir (112), an air inlet port in communication with a pressurized air source (120), and an outlet nozzle (114) spaced from and directed toward the moving substrate (20). The air gun (110) sprays controlled amounts of the powdered phosphor (102) onto the moving substrate (20), where the phosphor (102) assumes the temperature of the moving substrate (20). A laser (210) produces light pulses, and optics (200) direct the light pulses onto the phosphor (102) in response to which the phosphor (102) emits a luminescence with a decay rate indicative of the temperature of the phosphor (102). A collection lens (200) is disposed to focus the luminescence, and a photodetector (270) detects the luminescence focused by the collection lens (200) and produces an electrical signal that is characteristic of the brightness of the luminescence. A processor (300) analyzes the electrical signal to determine the temperature of the phosphor (102).