Lovibond Maxi Direct, Instruction Manual, Page: 82 / 268

80 MaxiDirect_2c 03/2010
1.1 Methods
DEHA (N,N-Diethylhydroxylamine)
with Tablet and Liquid Reagent
20 – 500 μg/l DEHA / 0.02 – 0.5 mg/l DEHA
1. Fill a clean vial (24 mm Ø) with
10 ml of the water
sample,
close tightly with the cap (Note 2).
2. Place the vial in the sample chamber making sure that
the marks are aligned.
3. Press ZERO key.
4. Remove the vial from the sample chamber.
5. Fill the vial with drops of the same size by holding the
bottle vertically and squeeze slowly:
6 drops (0.25ml) of DEHA solution
6. Close the vial tightly with the cap and swirl several times
to mix the contents.
7. Add one DEHA tablet straight from the foil to the
same water sample and crush the tablet using a clean
stirring rod.
8. Close the vial tightly with the cap and swirl several times
until the tablet is dissolved.
9. Place the vial in the sample chamber making sure that
the marks are aligned.
10. Press TEST key.
Wait for a
reaction period of 10 minutes
.
After the reaction period is finished the measurement
starts automatically.
The result is shown in the display as DEHA.
Countdown
10:00
prepare Zero
press ZERO
Zero accepted
prepare Test
press TEST
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