Fig. 2.

Measurements (black symbols) as well as reference values (RV, red lines) and laboratory biases (blue symbols, shifted) and their 95% CIs, estimated by fitting the fixed effect model (see Sec. 2.4) for the intrinsic absorption coefficient of undiluted India ink ε_a,ink (bottom row) and the intrinsic reduced scattering coefficient of IL ${\epsilon }_{s,\text{il}}^{\prime }$ (top row) at 3 different wavelengths. The laboratories are named using the ID number reported in Table 1.