MONITORING PHOSPHORESCENCE

摘要

A method of monitoring phosphorescence emitted by an article comprises exposing the article (2) to stimulating radiation (4), to generate a phosphorescent response from the article (2). The amplitude of the stimulating radiation oscillates between higher and lower magnitudes. The emitted phosphorescence is detected. The stimulating radiation is oscillated at a frequency with a period less than the decay time of the phosphorescence.