Physical Layout of the CD Module

Click here to see illustration with dimensions.

1. Incoming beam from monochromator.

2. Magnesium fluoride polarizer/beam splitter splits the light beam (1) into two linearly polarized beams each orthogonal to the other. Angle of divergence can be as small as 1° and as wide as 5°; standard divergence is 3 ° putting beams of light 3.5 mm apart at the center of the cyndrilical cell holder (3). Also, the 50 kHz Hinds PEM-90, which modulates each beam at 50 kHz rate, out of phase with each other. The two beams modulate/toggle between RCP and LCP 50 times per millisecond.

3. CD Cuvette holder, useful with both rectangular and cylindrical CD cuvettes. Two choices offered: jacketed for temperature regulation with circulating fluid (shown in chamber, 3a) and Peltier (shown outside chamber, 3b). An optional six-position cell changer is also available from Quantum Northwest, the the LC 600™.

4. Water lines to cuvettes 3 & 5.

5. Optional 1 cm² rectangle cell holders for rectangular cuvette for absorbance, fluorescence, and CD/2; jacketed for temperature regulation with circulating fluid.

6. Two photomultiplier tubes: UV/Vis or Vis/NIR optimized. Each reads into its own amplifier circuitry and its own fast 14 bit A/D converter. Mounted at a slight angle relative to each other. Detector panel can be easily replaced to accomodate NIR detection.

7. Port for detector for fluorescence detection CD, absorbance, and/or for photolyzing flash.

DSM Associated Hardware

1. Lamp
   PTI mirrored lamp housing to achieve a six-fold effective intensity in the lamp's output, achieving maximum light intensity from the 150 watt ozone producing xenon arc lamp. Cooling supplied by cooling box, below

2. Nitrogen Regulator
   Three independent channels for control of flow to lamp housing, monochromator, and sample compartment

3. Closed-Cycle Cooling Box
   An integrated closed cycle cooling system for lamp cooling which guarantees instantaneous lamp power supply shut down if cooling becomes compromised and runs lamp below ambient for long life.

4. Lamp Power Supply for 150 Watt Xe

5. 

   Electronics Box
   All external to spectrophotometer for greatest ease in diagnosing and repairing problems.

6. Computer
   Current best Pentium Microsoft Windows™ NT/2000 compatible computer with choice of LaserJet or DeskJet printer.