4 Units Description 
4-28
Figure 4-31 Position of Photometric Unit and AD Housing Assembly   
 
4.6.2.1  Light Source Assembly 
The light source assembly is composed of a filter wheel assembly, a lamp assembly, a light 
source seat, lenses, radiators, fans, a motor and a sensor. The main function is to provide a 
stable lignt source that emits a light beam to converge to the filter via lens. The filter of a 
specific wavelength is placed to the light path by rotating the filter wheel. Also a good cooling 
function for the lamp assembly is provided by the light source assembly.   
Figure 4-32    Light Source Assembly