Hanna Instruments c 99 Manuel D’Utilisation

10

The instructions listed below should be carefully followed during
testing to ensure best accuracy.

• Color or suspended matter in large amounts may cause interfer-

ence, therefore, these should be removed by treatment with active
carbon and by prior filtration.

• For a correct filling of the cuvet: the

liquid in the cuvet forms a convexity
on the top; the bottom of this convex-
ity must be at the same level of the
10 mL mark.

• In order to measure exactly e.g. 0.5 mL of sample or reagent

with the 1 mL syringe, push the plunger completely into the
syringe and insert the tip into the solution. Pull the plunger up
to above the 0.0 mL mark. Take out the syringe and clean the
outside of the syringe tip. Then, adjust the plunger to the 0.0 mL
mark (the lower edge of the seal must be exactly on the 0.0 mL
mark). 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 cuvet, push the plunger down 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 cuvet, even if the tip
still contains some reagent or sample.

• Proper use of the dropper: to get good

reproducible results, tap the dropper on the
table for several times and wipe the outside
of the dropper tip with a cloth. Always keep
the dropper bottle in a vertical position
while dosing the reagent.