| abstract |
To determine the concn. of substances in a biological sample, light is passed through a defined sample zone as prim. light for the emerging sec. light to be caught by a receiver. Spectroscopic measurements in frequencies are effected in at least two detection stages, where the prim. light is modulated with a HF modulation frequency, and the phase shift of the sec. light is registered against the prim. light together with intensity measurement values. In the evaluation stage, a scattered parameter is determined from the min. of two spectroscopic measurements, as a measurement of the light scatter in the biological sample and an absorption parameter as a measure of the light absorption in the sample. The substance concn. is derived from one of the parameters. |