In the present study chemical dosimeters having aqueous solutions of the Sandal Fix Red C4BLN (C.I. Reactive
Blue195A) dye were irradiated by Co60 γ-radiation source in the range 0-1kGy. Absorbance of exposed samples
was studied at λmax of the dye at pre and post irradiation. Radiation interaction with water produced free radicals
which consequently increased the acidity of the dye solutions, so the effect of the pH on the response was
preferably studied. The proportionality between the absorbance (A) and the concentration (C) of the dye was
checked (Validity of Beer’s Law). The theoretically proved exponential behavior of the curves between absorbed
dose (D) and the absorbance (A) was also taken into account. The exposure of γ-irradiation on the dye solutions
showed a linear function with positive slope between the negative logarithm of absorbance (-logA) and the
absorbed dose (D). Optimum concentration of the dye was selected from the plotted concentration at which it
could be used as the dye dosimeters.
