Hach Lange astroTOC Basic User Manual page 32

Clean the IR cell
Electrocution hazard. Remove all power from the instrument and relay connections before this
maintenance task is started.
Clean the IR cell at least once a year or when results become irregular. Refer to the illustrations in
this section for IR cell removal.
1. Remove the inlet and outlet tubing from the IR cell. Refer to
2. Support the mirror assembly to prevent the cell assembly from falling out if the thumb latch
releases unexpectedly. Refer to
3. Cut the tie wrap. Refer to
4. Pull the thumb latch away from the cell assembly to release it. Refer to
5. Clean the interior wall of the cell assembly with lint-free tissues and isopropyl alcohol. Refer to
Figure 17.
6. Use cotton swabs and isopropyl alcohol to clean the sapphire window that protects the parabolic
mirror. Refer to Figure
7. Do an inspection of the assembly to make certain that all debris and contamination are fully
removed and that the sapphire is not scratched or cracked.
8. Make sure that the parabolic mirror is not discolored. If the mirror is discolored or the sapphire is
damaged, replace the cell assembly.
9. Clean the sapphire window in the IR bench with the same procedure used to clean the cell
assembly window. Refer to
10. Remove the O-ring between the cell and the bench assembly.
11. Do an inspection of the O-ring and look for damage, debris or deterioration. Install a new O-ring if
the O-ring shows damage, debris or deterioration.
12. Do an inspection of the inlet and outlet ports for obstructions or contamination. Remove
obstructions or contamination with cotton swabs and isopropyl alcohol.
13. Install the tubing and a new tie wrap.
14. Do a pressure/leak test. Refer to
32 English
D A N G E R
Figure 18 on page 35.
Figure 18 on page 35.
17.
Figure 17.
Pressure/leak test
Figure 18 on page 35.
Figure 18
on page 33.
on page 35.