62 Model 7500 Instruction Manual
Teledyne Analytical Instruments
7.3 Cleaning of measuring cell
Entry of dust or water drops in the measuring cell contaminates the interior of the cell, thus resulting in
a drift. Clean the inside if dirty. Then, check the sampling device, especially the lter, to prevent the cell
from being contaminated by dust or mist.
7.3.1 Disassembly and assembly of measuring cell
There are two kinds of measuring cells, on block cells (cell length: 4 mm, 8 mm, 16 mm, 32 mm) and pipe
cells (Cell length: 6.4 mm, 125 mm and 250 mm). 2-component analyzer may incorporate both measuring
cells in optical unit. In such a case, detach the pipe cell and then block cell (See Fig. 7-1).
(1) How to remove pipe cell (See Fig. 7-1)
1. Stop measured gas. If it is harmful, purge in the measuring cell thoroughly with zero gas.
2. Turn OFF the power switch.
3. Detach the top cover.
4. Remove the pipe connected to the measuring cell.
5. Slide the infrared ray light source unit (No. 5) toward the front panel by loosening the screw
(No. 1) fastened to the base plate to provide clearance between the pipe cell (No. 12)
and light source unit.
6. Loosen and remove a screw (No. 7) from the cell retainer (No. 11) fastening the pipe cell.
7. Remove the cell from the measuring unit and unscrew the infrared transmission window
(No. 14) at the both ends in the right direction.
Note: The reection plate in the cell is not closely attached to the cell.
8. For assembly, reverse the disassembly procedure. Provide 0.5 mm clearance between the
infrared ray light source unit and cell, and the cell and detector, respectively.