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19
PHO
TOMETER MODE
6.2. COLLECTING AND MEASURING SAMPLES AND REAGENTS
6.2.1. PROPER USE OF SYRINGE
(a) Push the plunger completely into the syringe and insert the tip
into the solution.
(b) Pull the plunger up until the lower edge of the seal is exactly on
the mark for the desired volume.
(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.
Then, keeping the syringe in vertical position above the
cuvette, push the plunger down into the syringe, the desired
volume has been delivered into the cuvette.
6.2.2. PROPER USE OF DROPPER
(a) For reproducible results, tap the dropper on the table several times and wipe the outside of the
tip with a cloth.
(b) Always keep the dropper bottle in a vertical position while dosing the reagent.
6.2.3. PROPER USE OF POWDER 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.