“…Many radiation-sensitive compounds can be used to prepare such dosimeters. For example, a group of tetrazolium salts transforming into colored formazans [ 3 , 4 , 5 , 6 , 7 ] have been intensively studied as components of poly(vinyl alcohol) films in the kilogray dose range, such as 2,3,5-triphenyltetrazolium chloride [ 8 ], nitro-blue tetrazolium chloride [ 9 ], ethyl violet-bromophenol blue dyed [ 10 ], 2,3,5-triphenyltetrazolium chloride, neotetrazolium chloride, 5-(p-nitrophenyl)-2,3-diphenyltetrazolium bromide, 2,5-diphenyl-3-(1-naphthyl)tetrazolium bromide, and 2,2’-di(p-nitrophenyl)-5,5’-diphenyl-3,3’-(3,3-dimethoxy-4,4’-diphenylene)-2H-ditetrazolium chloride (nitrotetrazolium blue chloride, NBT) [ 11 ]. Other films were also used to prepare dosimeters, such as polyvinyl butyral with nitro-blue tetrazolium [ 12 ] or methyl red [ 13 ].…”