Hanna Instruments HI 96733 - Manual (Page 7)

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• It is important that the sample does not contain any debris.
This would corrupt the reading.
• In order to avoid reagent leaking and to obtain more
accurate measurements, it is recommended to close the
cuvette first with the supplied HPDE plastic stopper and
then with the black cap.
• Each time the cuvette is used, the cap must be tightened
to the same degree.
• Whenever the cuvette is placed into the measurement
cell, it must be dry outside, and completely free of
fingerprints, oil or dirt. Wipe it thoroughly with HI 731318
or a lint-free cloth prior to insertion.
• Shaking the cuvette can generate bubbles in the sample, causing higher readings. To obtain
accurate measurements, remove such bubbles by swirling or by gently tapping the cuvette.
• Do not let the reacted sample stand too long after reagent is added, or accuracy will be lost.
• It is possible to take multiple readings in a row, but it is recommended to take a new zero
reading for each sample and to use the same cuvette for zeroing and measurement.
• After the reading it is important to discard immediately the sample, otherwise the glass
might become permanently stained.
• All the reaction times reported in this manual are referred to 20°C (68°F). As a general rule
of thumb, they should be doubled at 10°C (50°F) and halved at 30°C (86°F).
• In order to maximize accuracy, prior to a measurement follow the validation procedure to
be sure that the instrument is properly calibrated. If necessary, calibrate the instrument.
MEASUREMENT PROCEDURE
STARTUP
Prepare the instrument for measurement as follows:
• Unpack the instrument by removing the dust protection sleeve from the instrument cuvette
holder.
• Place the battery in the instrument as described in the “BATTERY REPLACEMENT” chapter.
• Place the instrument on a flat table.
• Do not place the instrument under direct sun light.
To compensate the meter for the sample turbidity or color, the measurement takes place in two
phases. First, the meter is zeroed using the unreacted sample. After the reagents are added the
reacted sample is measured.
• When the beeper sounds briefly and the
LCD displays dashes, the meter is ready.
The blinking “ZERO” indicates that the
instrument needs to be zeroed first.
• Fill one cuvette with 1 mL of unreacted
sample, by means of the syringe.
• Using the plastik pipette, add 9 mL of
HI93733B-0 Ammonia Reagent B, up to
the 10 mL mark. Place the cap and swirl
the solution to mix.
• Turn the meter on by pressing ON/OFF.
The display briefly shows all tags on.
• Proper use of dropper:
(a) to get good reproducible results, tap the dropper on the table for several times and wipe
the outside of the dropper with a cloth.
(b) always keep the dropper bottle in a vertical position while dosing the reagent.
(a) (b)
10 mL
sample