OPERATIONAL GUIDE
MEASUREMENT PROCEDURE
• Turn the meter on by pressing
ON/OFF.
• When the LCD displays "- - -",
it is ready.
• Add to the cuvet 6 mL of
sample and replace the cap.
• Place the cuvet into the holder
and ensure that the notch on
the cap is positioned securely
into the groove.
• Press ZERO and "SIP" will appear on the display.
• Wait for a few seconds and
the display will show "-0.0-".
Now the meter is zeroed and
ready for measurement.
• Remove the cuvet and add
the content of one packet of
HI 93728 reagent.
• Replace the cap and
immediately shake
vigorously for exactly
10 seconds by
moving the cuvet up
and down. Continue
to mix by inverting
the cuvet gently and
slowly for 50 seconds,
while taking care not to induce air bubbles. A deposit could
remain but it does not affect the measurement. Time and
way of shaking could sensitively affect the measurement.
ON
OFF
ZERO
• Reinsert the cuvet into the
instrument, taking care not
to shake it.
• Press READ TIMED and the display will show the countdown
prior to the measurement or, alternatively, wait for 4
minutes and 30 seconds and press READ DIRECT. In
both cases "SIP" will appear during measurement.
• The instrument directly displays concentration in mg/L of
nitrate-nitrogen on the Liquid Crystal Display.
• To convert the reading to mg/L of nitrate (NO
3
–
),
multiply by a factor of 4.43.
INTERFERENCES
Interference may be caused by:
Ammonia and amines, as urea and primary aliphatic
amines
Chloride above 100 ppm (negative interference)
Chlorine above 2 ppm (positive interference)
Copper (it must be absent)
Iron (III) (positive interference)
Strong oxidizing and reducing substances
Sulfide (it must be absent)
Note:
To ensure accurate results, perform the tests at room
temperature, between 18°C and 28°C (65F to 83F).
For best results:
Intensely colored samples or suspended
matter in large amounts will cause interference.
Therefore sample should be adequately treated before
performing the test.
READ
TIMED
The instruction listed below should be carefully followed
during testing to ensure best accuracy.
• Do not touch the cuvet walls with hands.
• In order to maintain the same conditions during the
zeroing and the measuring phases, it is necessary to
close the cuvet to prevent any contamination.
• Do not let the test sample stand too long after reagent
is added or accuracy will be lost.
• Whenever the cuvet is placed into the measurement cell,
it must be completely free of fingerprints, oil or dirt.
Wipe it thoroughly with
HI 731318
or a lint-free cloth
prior to insertion.
• It is important that the sample does not contain any
debris. This would corrupt the readings.
• It is possible to take multiple readings in a row, but it
is recommended that a zero reading be taken for each
sample and that the same cuvet is used for zeroing and
measurement.
• It is important to discard the sample immediately after
the reading is taken because the glass may become
permanently stained.
• Shaking the cuvet can generate bubbles in the sample,
causing higher readings. To obtain accurate measure-
ments, remove such bubbles by swirling or by gently
tapping the vial.
• All the reaction times reported in this manual are
referred to 20°C (68°F). As a general rule, they should
be doubled at 10°C (50°F) and halved at 30°C (86°F).
TIPS FOR AN ACCURATE
MEASUREMENT
BATTERY REPLACEMENT
Battery replacement must only take place in a non-hazardous
area using a 9V alkaline battery.
Simply slide off the battery cover on the back of the meter.
Detach the battery from the terminals and attach a fresh
9V battery while paying attention to the correct polarity.
Replace the battery and the cover.
9V
SLIDE
OFF
Recommendations for Users
Before using these products, make sure that they are entirely suitable for the environment
in which they are used.
Operation of these instruments in residential area could cause unacceptable interferences
to radio and TV equipments, requiring the operator to take all necessary steps to correct
interferences.
Any variation introduced by the user to the supplied equipment may degrade the
instruments' EMC performance.
To avoid damages or burns, do not perform any measurement in microwave ovens.
ACCESSORIES
REAGENT SETS
HI 93728-01
Reagents for 100 tests
HI 93728-03
Reagents for 300 tests
OTHER ACCESSORIES
HI 710009
Blue rubber boot
HI 710010
Orange rubber boot
HI 721310
9V battery (10 pcs)
HI 731318
Tissue for wiping cuvets (4 pcs)
HI 731321
Glass cuvets (4 pcs)
HI 731325
Caps for cuvets (4 pcs)
HI 93703-50
Cuvets cleaning solution (230 mL).
CE DECLARATION
OF CONFORMITY
IST93728R3 10/02
12
3
6
9
4’30"
READ
DIRECT
