4 Units Description 
4-30
4.6.3  Dismounting and Mounting Photometric Unit 
Figure 4-35 Dismounting Photometric Unit   
 
Dismounting steps are as follows. 
1.  Remove the  rear  panel  of  the  analyzer and  the  table  panel  1  above  the  light 
source aassembly. 
2.  Remove the light source assembly: Loosen the three M4X20 socket screws and 
unplug  the  connectors of  the  lamp  wire,  the  fan  wire,  the  motor  wire  and  the 
sensor wire. And then remove the light source assembly. 
3.  Remove the forward optics assembly: Remove the reaction disk cover and the 
reaction disk. Loosen the three M4X16 socket screws and remove the forward 
optics assembly. 
4.  Remove  the  pre-amp  housing  assembly:  The  pre-amp  housing  assembly  is 
installed on the forward optics assembly. Unscrew the two M3X16 socket screws 
and remove the pre-amp housing assembly. 
5.  Reserve the steps described above to mounting the photometric unit 
6.  Dismounting and mounting the AD housing is independent on what to do with the 
light source assembly and the forward optics assembly. 
Precautions: 
1.  The light source assembly should be inclined slightly to the reaction disk when 
removed together with the dustproof cover. Be careful not to scrape the filter. 
2.  You can remove the dustproof cover and then remove the light source assembly. 
Thus it is easier to operate. 
3.  The forward optics assembly is connected with the reaction disk by matching the 
two pins at the bottom of the optics seat with the two corresponding pin holes in 
the reaction disk. It may be tight when taking out the forward optics assembly due 
to the firm conjunction. 
4.  Unplug the connectors of the wire before removing the assemblies and plug the 
connectors after installation. 
5.  Be careful not to scrape the surface of the filter when removing the light source 
assembly.