CETAC M-7600 Mercury Analyzer Operator's Manual

CETAC QuickTrace M-7600 Mercury Analyzer
Chapter 5: Maintaining the Mercury Analyzer
Removing the Sample Cell
Refer to Figure 5-3 and Figure 5-4. The cells are designed for simple removal
and cleaning. When removing the cells, be careful to not touch the cell
windows at the ends of the optical cells. If the cells and cell windows are dirty,
use a clean foam swab and isopropyl alcohol (spectrophotometric grade only)
to clean the surfaces (see page 107). If needed, the windows can be taken out
by removing the end caps and the O-rings.
Once the cell clamps have been removed, disconnect the carrier gas tubes from
the cell end caps. Remove the cell end caps by holding the glass cell, pull, and
rotate the end cap until it slides off the glass cell. Repeat this procedure for the
reference cell. Inspect and/or clean the cell and its windows per the
instructions beginning on page 107, or perform tubing maintenance as
described in on page 113.
Cleaning the Cell Windows
Refer to Figure 5-4.
There are two ways to clean cell windows:
‣ Quick exposed surface cleaning (without dismantling).
‣ Dismantling for total cleaning.
The need for cleaning (or re-cleaning) is determined by close inspection of the
window (D in Figure 5-4), visible through the hole in the window cap (A),
while maintaining a low-angle total surface reflection of room light on the
window. Any film, fingerprint, dust, or dirt will show up dramatically against
the “white” background of a low-angle surface reflection of room light from the
window.
Quick Exposed Surface Cleaning
Cleaning the exposed surface of the window requires the following: a clean
foam swab, Kimwipes ® wipers, and a bottle of isopropyl alcohol (use only
spectrophotometric grade).
NOTE
Do NOT use cotton swabs. They will leave small bits of lint, which can offset the
absorbance baseline and add a great deal of noise, if the lint moves or flutters
in the optical beam. Use only clean foam swabs. To pre-clean the foam swab,
rinse in alcohol and dry with a KIMTECH SCIENCE KIMWIPES® delicate task
wiper. Do not dip the swab in the alcohol supply (when new, the swabs may be
dirty and contaminate the alcohol supply). Instead, squirt alcohol onto the
swab with a wash-bottle that is for alcohol only and dry with the Kimwipes®
wiper. Rinse and only lightly blot the swab with Kimwipes® wipers when
cleaning; this will leave the swab moist with alcohol, which will be enough to
clean the cell windows.
Using the pre-cleaned, alcohol-moistened swab, gently swab the outside of the
cell window. Wipe with a Kimwipes ® wiper and blow-dry with UHP Argon or
Nitrogen. The blow-drying will also remove any lint or dust that may have
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