75
Checking your meter
7
Open a bottle of control solution.
8
Wipe the tip of the dropper with a clean, dry
paper towel to remove any dried-on residues.
9
Invert the bottle and hold it downwards at an
angle. Squeeze it gently until a small drop which
is free of any air bubbles is suspended from the
tip.
10
Apply
one
drop to the centre of the orange field
without touching it with the tip of the dropper.
The field must be completely covered with
solution.