Figure 4.

Spectral characteristics of DLOS LED light source and PRESAGE response to dose (ΔODcm⁻¹ Gy⁻¹). It is important to avoid spectral artifacts arising from preferential absorption in PRESAGE of light at different wavelengths. An effective solution is to apply a narrow band-pass filter (Filtered LED) to ensure consistent absorption at all wavelengths [analytic corrections are also described in Thomas et al. (Ref. ²⁹)].