Simple optical readout for ethanol-chlorobenzene dosimetry system

Optical readout of the ethanol-chlorobenzene (ECB or Dvornik dosimetry system) is based on the development of coloured secondary complex of ferric thiocyanate which has a maximum absorption at 485 nm. The applicability of a rugged, hand-held, battery powered filter colorimeter operating at 480 nm has been investigated as a reader for this purpose. This simple reader performs very well within absorbance displaying an excellent linearity of absorbance with the concentration of Cl⁻ ions. It was shown, by choosing the appropriate dilution factor when preparing the secondary complex solution, the entire useful dose range of the dosimeter up to 2 MGy can be covered. The applicability of the same reader to some other liquid chemical dosimeters is also discussed.