Precision analogue divider system for fast circular dichroism measurement and other applications requiring rapid radiometry

A two-quadrant divider system is described for accurate analogue computation of the ratio Q=10 N/D. Errors in Q are less than 0.1%, rise time 3 mu s, dynamic range and common-mode rejection 60 dB. Although designed for circular dichroism measurements in the microsecond time range, it has been applied to other measurements needing precision or fast analogue division: spectroscopic source ratioing, laser speckle vibrometry and sound pressure correction.