Assessment of colorimetric reading out methods for radiochromic film and red radiation-sensitive poly-methylmethacrylate

This research is aimed to introduce and to compare 3 methods of reading out and analyzing light blue radiochromic film (BLF) dosimeter and red radiation-sensitive poly-methylmethacrylate (PMMA). The BLF and red radiation-sensitive PMMA act as a colour detector which its colour changes after being irradiated. These dosimeters are usually used in food irradiation for process control during irradiation process. The camera-based measurement in a constraint condition, scanner-based measurement with the Trichromatic Colour Analyser (TCA) software and spectrophotometer were used for obtaining colorimetric data of both dosimeters which were non-irradiated and irradiated in 5 doses: 5, 10, 15, 20 and 25 kGy. There were strong linear relationships between doses, given to BLF, and lightness (CIE L*), chroma (CIE C*) and yellowness-blueness (CIE b*) for 3 methods. For red radiation-sensitive PMMA, strong linear relationships were found between doses and redness-greenness (CIE a*) as well as CIE C* in both TCA and spectrophotometer methods. The doses and CIE L* gave strong relationship only in the spectrophotometric method.