28
AL100_7 07/2016
GB
Methods
Urea
with Tablet and Liquid Reagent
0.2 – 5 mg/l (NH
2
)
2
CO
Fill a clean vial (24 mm Ø) with
5 ml of the water sample
and
5 ml
deionised water
, close tightly with the cap.
Place the vial in the sample chamber making sure that the marks
are aligned.
Press the [ZERO/TEST] key.
The method symbol flashes for approx. 8 seconds.
Remove the vial from the sample chamber.
In the presence of free Chlorine (HOCl), add
one UREA PRETREAT
tablet
straight from the foil and crush the tablet using a clean stirring
rod (Note 10).
Close the vial tightly with the cap and swirl several times to mix the
contents.
Fill the prepared vial with drops of the same size by holding the bottle
vertically and squeeze slowly:
2 drops of UREA Reagent 1
Close the vial tightly with the cap and invert several times to mix the
contents.
Add
1 drop of UREA Reagent 2
(Urease) to the same water sample.
Close the vial tightly with the cap and invert several times to mix the
contents.
Wait for a
reaction period of 5 minutes
.
Add
one AMMONIA No. 1 tablet
straight from the foil to the pre-
pared water sample and crush the tablet using a clean stirring rod.
Add
one AMMONIA No. 2 tablet
straight from the foil to the same
water sample and crush the tablet using a clean stirring rod.
Close the vial tightly with the cap and swirl gently several times until
the tablets are dissolved.
Place the vial in the sample chamber making sure that the marks
are aligned.
Wait for a reaction period of 10 minutes.
(Countdown can be activated, see page 25)
The method symbol flashes for approx. 3 seconds.
The result is shown in the display in mg/l Urea.
Tolerances:
± 0.4 mg/l Urea
RESULT
!
Zero
Test
0.0.0
Ur2
Ur2
Zero
Test
Ur2
