Hach Lange 2100AN Basic User Manual page 14

• Keep the sample compartment lid closed to keep dust and dirt out.
Sample cells
• Always cap the sample cell to prevent spillage of the sample into the
instrument.
• Always use clean sample cells in good condition. Dirty, scratched or
damaged cells can result in readings that are not accurate.
• Make sure that cold samples do not "fog" the sample cell.
• Store sample cells filled with distilled or deionized water and cap
tightly.
• For the best accuracy, use a single sample cell for every
measurement or a flow cell.
Turbidity measurement procedure
1. Rinse a clean, 2. Clean the sample
empty sample cell two cells with a soft, lint-free
times with the solution cloth to remove water
to be measured and spots and fingerprints.
drain to waste. Fill to
the line (about 30 mL)
with sample and
immediately put the cap
on the sample cell.
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Note: As an alternative, matched sample cells may be used for measurements but
do not provide as good of accuracy or precision as a single indexed sample cell or
flow cell. When using matched sample cells, align the orientation mark on the
sample cell with the reference mark on the sample cell holder.
Measurement
• Measure samples immediately to prevent temperature changes and
settling. Before a measurement is taken, always make sure that the
sample is homogeneous throughout.
• Avoid sample dilution when possible.
• Avoid instrument operation in direct sunlight.
3. Apply a small bead 4. Use the oiling cloth
of silicone oil from the provided to apply the oil
top to the bottom of the equally to the surface of
sample cells. the sample cells.
Remove the excess oil.
Make sure that the
sample cells are almost
dry.
5. Gently and slowly 6. Put the sample cell
invert the sample cell to in the sample cell
fully mix the sample. Be holder with the triangle
careful not to add air on the sample cell
bubbles. aligned with the
reference mark on the
sample cell holder.
Close the cover.