Wenderoth, Lind & Ponack
Spectrophotometer
 In a spectrophotometer of double beam type comprising a radiation source, reference and sample cells, a photo detector, and beam path switching means, a current-voltage converting amplifier and a logarithmic amplifier in parallel connection are connected to the photo detector. In measuring the transmittance of a sample material in the sample cell, an output of the detector responding to a sample cell transmitted beam is directly supplied to the logarithmic amplifier without undergoing current-voltage conversion while an output of the detector responding to a reference cell transmitted beam is supplied to the current-voltage converting amplifier without undergoing logarithmic amplification. 
Japan Spectroscopic Co., Ltd.
G G
G01N G01J
additional inventional
Shinichiro
Watanabe