13
2.
In order to measure exactly e.g. 0.5 mL of reagent with the 1 mL
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 0.0 mL mark.
(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 vial, 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 vial, even if the tip still contains some solution.
• Color or suspended matter in large amounts may cause interference,
therefore, these should be removed by treatment with active carbon
and by prior filtration.
USING LIQUID AND POWDER REAGENTS
• Proper use of the dropper:
(a) 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.
(b) always keep the dropper bottle in a vertical position while
dosing the reagent.
(
a
)
(
b
)
(
c
)
(
a
)
(
b
)
68
• Select the program number corresponding to Reactive Phosphorus
High Range on the secondary LCD by pressing PROGRAM
t
and
s
.
• Remove the cap from two Reagent Vials.
• Add exactly 5.0 mL of sample to one vial (sample vial), and 5.0
mL of deionized water to the other vial (blank vial), while keeping
the vials at a 45-degree angle.
• Replace the cap and mix by inverting each vial a couple of times.
•
Place the blank vial into the holder
and push it completely down.
•
Press TIMER and the display will show the countdown prior to the
measurement. Alternatively, wait for 7 minutes and press ZERO. In
both cases "SIP" will blink during measurement.
•
Wait for a few seconds and the
display will show “-0.0-”. Now the
meter is zeroed and ready for
measurement.
•
Remove the blank vial.
Phosphorus, Reactive HR