The tissue spectrometer EMPHO allows measurements of absolute hemoglobinoxygenation values, noninvasive1y at any hemoglobin-perfused tissue, simply by applying visible light on the surface of theorgans under investigation. The hemoglobin oxygenation-algorithm is based on Kubelka-Munk-Theory fortackling both. absorbance and scattering phenomena. Broad-band tissue spectra ofbackscattered light serves as data basis for the analysis. In this study the algorithm was tested for measurements in highly scatteringmedia, in Intralipid©, where erythrocytes were added step by step. The hemoglobin concentration in the suspension varied from 0.01 to 1.0 [g hb Idl of suspension], which corresponds to the range of hemoglobin concentrations physiologically found in various types of tissue. The oxygenation was changed from 0 % to 100 % by using a hollow-fibre oxygenator. The costly study revealed that the algorithm works with high accuracy at a middlehemoglobin-concentration of 0.3 g/dl. The error of calculation was smaller than 2% of the absolute HbO value. The statistics proved that errors were larger at the highest and lowest values o hemoglobin concentration. It could clearly be shown that the errorcan be minimized to 1 % by application ofnew gold-standard hemoglobin spectra ofO % and 100 % oxygenation. Key words: tissue spectrometry, hemoglobin oxygenation, Kubelka-Munk Theory, light absorbance,light scattering, visible wavelength range.