Characterisation and evaluation of a miniaturised polyphenylene oxide dosimeter for ultraviolet exposures

Dosimeters are used in measuring received ultraviolet (UV) radiation by humans and plants. Previously dosimeters 3.0cm×3.0cm weighing 0.6g, using poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)(1) as the photoactive material have been used. A smaller 1.0cm×1.5cm flexible PPO dosimeter weighing 0.05g has been developed and characterised in this research. Laboratory and field studies show that the miniaturised dosimeter measures comparative results to the larger dosimeters for cosine response, dark reaction and dose response. The smaller, flexible dosimeters are also more applicable for use on curved surfaces and have less impact on the orientation of plant leaves due to their decreased mass. This research has also shown that miniaturised PPO dosimeters can be successfully employed on plant and human subjects to accurately determine biologically active UV distributions. The miniaturised PPO dosimeters allow for more measurements over an exposed area and the PPO film allows for measurements to be made for periods longer than 1day. The combination of smaller size and longevity of the photoactive material allows for more flexibility in future UV field research resulting in an increase in the potential number of environments where UV dosimeters can be deployed.