Preparing a cuvette and inserting it into the instrument
Rinse the cuvette several times with the sample solution.
Wipe the outside of the cuvette with a laboratory tissue to remove
fingerprints. Check for air bubbles. If there are air bubbles
in the sample, gently tap the cuvette to displace the bubbles.
If the bubbles persist, thoroughly clean the cuvette, rinse it
with solution, and refill it. Insert the cuvette into the sample
compartment. Align an index mark near the top of the cuvette with
a mark on the sample compartment. Align the cuvette the same way
for each reading. Close the sample compartment lid.