8
9
(c) take out the syringe and clean the outside of the syringe tip. Be sure that no drops are hanging
on the tip of the syringe, if so eliminate them. Then, keeping the syringe in vertical position above
the cuvette, push the plunger down into the syringe until the lower edge of the seal is exactly on
the 0.5 mL mark. Now the exact amount of 0.5 mL has been added to the cuvette, even if the
tip still contains some solution.
USING LIQUID AND POWDER REAGENTS
• Proper use of the dropper:
(a) for reproducible results, tap the dropper on the table for several times and wipe the outside of the
dropper tip with a cloth.
(b) always keep the dropper bottle in a vertical position while dosing the reagent.
• Proper use of the powder reagent packet:
(a) use scissors to open the powder packet;
(b) push the edges of the packet to form a spout;
(c) pour out the content of the packet.
(a)
(b)
(a)
(c)
(a)
(b)
shake gently
shake vigorously
(b)
(c)
USING CUVETTES
• Proper mixing of the cuvette is done by
shaking the cuvette
, moving the cuvette up and down. The
movement may be gentle or vigorous. This mixing method is indicated with “shake gently” or “shake
vigorously”, and one of the following icons:
Pay attention to push the cuvette completely down in the holder.
• In order to avoid reagent leaking and to obtain more accurate measure-
ments, close the cuvette first with the supplied HDPE plastic stopper
and then the black cap.
• Each time the cuvette is used, the cap must be tightened to the same degree.
• Whenever the cuvette is placed into the measurement cell, it must be dry
outside, and free of fingerprints, oil or dirt. Wipe it thoroughly with
HI 731318
or a lint-free cloth prior to insertion.
• Shaking the cuvette can generate bubbles in the sample, causing higher
readings. To obtain accurate measurements, remove such bubbles by
swirling or by gently tapping the cuvette.
• Do not let the reacted sample stand too long after reagent is added, or
accuracy will be lost.