Hach Lange 2100AN, Instrument Manual

Page: 22 / 108

22
SECTION 2,
continued
2.3.4.2 Matching Sample Cells
Index match (orientation) multiple cells using the following procedure. Matched
cells also can be used for measuring in Transmittance, Color or Absorbance:
1.
Add portions of the
high-quality dilution
water to multiple cells that
are clean and coated with
silicone oil (refer to
Section 2.3.1, and
Section 2.3.2 on page 18,
and Section 2.3.3 on
page 19.
2.
Insert the appropriate
filter module.
3.
Insert the first cell into
the instrument. Rotate the
cell slightly until the
lowest reading is found.
Note the cell orientation,
record the reading, and
add a permanent index
mark to the marking band
of the cell.
4.
Insert the second cell
into the instrument, close
the lid, and note the value.
Rotate the cell about
1
/
8
of
a turn and observe the
reading. Repeat
1
/
8
-turn
rotations until the reading
matches the first cell
reading within
±
0.01 NTU
.
Add a
permanent orientation
mark to the marking band
of the second cell. Repeat
this procedure to match
other cells.
Note: It may not be possible
to match all cells due to
variability in glass.
Note: Match sample cells
within ± 0.002 absorbance
units when indexing cells in
the absorbance mode for use
with Transmittance, Color or
Absorbance measurements.