LaMotte Fresh Water Aquaculture - Manual (Page 21)

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Insert the tip of the Titraror
into the opening of the
titration tube cap.
Slowly depress the
plunger to dispense the
titrating solution until
the yellow-brown color
changes to a very pale
yellow. Gently swirl the
tube during the titration
to mix the contents.
Carefully remove the
Titrator and cap. Do
not disturb the Titrator
plunger. Add 8 drops of Starch
Indicator Solution
(4170WT). The sample
should turn blue.
Cap the titration tube.
Insert the tip of the
Titrator into the opening
of the titration tube cap.
Continue titrating until the blue
color disappears and the solution
becomes colorless.
NOTE: If the plunger ring
reaches the bottom line on
the scale (10 ppm) before the
endpoint color change occurs,
refi ll the Titrator and continue
the titration. Include the value
of the original amount of
reagent dispensed (10 ppm)
when recording the test result.
Read the test result directly from the scale
where the large ring on the Titrator meets
the Titrator barrel. Record as ppm Dissolved
Oxygen. Each minor division on the Titrator
scale equals 0.2 ppm.
NOTE: When testing is complete, discard the
titrating solution in the Titrator. Rinse Titrator
and titration tube thoroughly. DO NOT remove
plunger or adapter tip.
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