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• The instrument directly displays concentration in
mg/L of ammonia
nitrogen
(NH
3
-N) on the Liquid Crystal Display.
• To convert the reading to mg/L of ammonia (NH
3
), multiply by a
factor of 1.214.
INTERFERENCES
Interference may be caused by:
• Organic compounds like: chloramines, various aliphatic and aromatic
amines, glycine or urea above 10 ppm N (positive error).
To eliminate these interferences distillation is required.
• Organic compounds like: aldehydes, alcohols (e.g. ethanol) or
acetone above 0.1 % (negative error).
To eliminate these interferences distillation is required.
• Sulfide: may cause turbidity.
Ammonia LR
57
• 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 93758-0
Phosphorus Reagent.
•
Replace the cap tightly and shake
gently to mix for 2 minutes until
most of the powder is dissolved. This
is the reacted sample.
•
Place the vial into the holder and
push it completely down. Ensure that
the vial orientation respect to the
holder is the same as the blank.
• Press TIMER and the display will show the countdown prior to the
measurement. Alternatively, wait for 3 minutes and press READ
DIRECT. In both cases "SIP" will blink during measurement.
Phosphorus, Reactive