Question 3 answer

· Radiant energy source

· Monochromator: Entrance slit, Diffraction grating, Exit slit

· Cuvette

· Detector (PMT)

· Readout device

· Enhancements: lenses, mirrors, fiber optics

· Monochromator: Must have single desired wavelength separated from other wavelengths. Has entrance slit (focuses narrow beam of light on dispersing device), wavelength dispersing device (diffraction grating or prism which separates light into dispersed monochromatic wavelengths), and exit slit (blocks/selects range of wavelengths that can reach detector).

o Photodiode array detectors: can monitor light at multiple wavelengths simultaneously (for example, 340 to 800 nm at resolution of 1 nm)