The present invention relates to an improved dual beam multichannel spectrophotomer employing a simple and novel optical system in combination with photodiode arrays and a unique logrithmic data converter to convert light signals to absorbance. In particular, the optical system utilizes optical elements...http://www.google.de/patents/US4848904?utm_source=gb-gplus-sharePatent US4848904 - Dual beam multichannel spectrophotometer with a unique logarithmic data converter
