User Guide

35
• Replace the cap tightly and
invert
the vial 10 times. This is the blank.
Warning: as the vial becomes hot
during mixing, be careful in handling
it.
Note: the method is technique sensitive: to obtain reproducible
results it is strongly recommended to follow carefully the “invert”
procedure described on page 14.
• Mark the vial with a pencil on the
white band to place an orientation
sign. Use this sign to insert the test
vial always in the same position into
the holder.
• Place the vial into the holder and
push it completely down.
• Press ZERO and “SIP” will blink 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 vial.
• Remove the cap and add the content
of one packet of HI 93766-0 Nitrate
Reagent.
• Replace the cap tightly and
invert
the vial 10 times. This is the reacted
sample.
Note: the method is technique
sensitive: to obtain most reproducible
results it is strongly recommended
to follow carefully the “invert”
procedure described on page 14.
Nitrate
46
• 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 5 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.
• Place the sample vial into the holder
and push it completely down.
• Press READ DIRECT and "SIP" will blink on the display.
• The instrument directly displays concentration in mg/L of total
nitrogen (N) on the Liquid Crystal Display. The method detects all
organic and inorganic forms of nitrogen present in the sample.
• To convert the reading to mg/L of ammonia (NH
3
), multiply by a
factor of 1.22.
• To convert the reading to mg/L of nitrate NO
3
-
, multiply by a factor
of 4.43.
INTERFERENCES
Interference may be caused by:
Bromide (Br
-
): above 240 mg/L (positive error)
Chloride (Cl
-
): above 3000 mg/L (positive error)
Chromium (Cr
3+
): above 0.5 mg/L
Nitrogen, Total HR