Page 100 - Tandem Techniques
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Page 81
Thus (a) can be controlled by varying (i). The rotational resolution (Da) for a controlled change in
current through the coils of (Di) can be as little as 10 but due to heat losses in the coil, the maximum
-5
value of (Da) is limited to about ± 2°. A diagram of the detector is shown in Figure 22.
Figure 2.23
A Chiral Detector Monitoring Optical Rotation
Courtesy of JM Science Inc.
Light from a tungsten lamp passes through two condenser lenses to a polarizer. Plane polarized light
from the polarizer passes through a temperature controlled cell, to a Faraday modulator and thence,
through an analyzer onto a photomultiplier. The modulator is supplied with a crystal-controlled AC
component. If an optically active sample is present,
