I am using the aqueous solutions containing active synthetic dyes (color pigments)... the response of the aqueous solutions in the form of Absorbance (A), is very confusing means anomalously in some of the dyes....not linearly or not in any proper way...so it causes confusion in selection of these color pigments (dyes) to be satisfactorily be used as dosimeters....
Another way is to use different methods (or compounds) for different ranges of dose. An example you find here: www.revistadechimie.ro/pdf/NEDELCU%20G.pdf
the cited paper shows the ferreous sulfate dosimetry, which was officialy used for years in Germany to calibrate our ionisation chambers to a 2 % error.