User Guide

25
SPECIFICATIONS
Range 0.0 to 50.0 mg/L
Resolution 0.5 mg/L
Accuracy ±0.5 mg/L ±4% of reading
Light Source Tungsten lamp with narrow band interference fil-
ter @ 420 nm
Method Adaptation of the ASTM Manual of Water and
Environmental Technology, D1426-92, Nessler
method. The reaction between ammonia and re-
agents causes a yellow tint in the sample.
REQUIRED REAGENTS
Code Description Quantity
HI 93715A-0 First Reagent 4 drops
HI 93715B-0 Second Reagent 4 drops
REAGENT SETS
HI 93715-01 Reagents for 100 tests
HI 93715-03 Reagents for 300 tests
For other accessories see page 56.
MEASUREMENT PROCEDURE
10 mL
Note: for sample preparation follow the NUTRIENTS SOLUTION (MR)
procedure at page 20.
• Select the program number 2 “Ammonia MR” on the secondary
LCD by pressing PROGRAM M and L.
• Fill the cuvet with 10 mL of unreacted sample, up
to the mark, 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 blink on the display.
Ammonia MR
AMMONIA MEDIUM RANGE
36Nitrate MR
• Remove the cuvet and add the content of one
packet of HI 93728 reagent.
• Replace the cap and imme-
diately shake
vigorously for
exactly 10 seconds by mov-
ing the cuvet up and down.
Continue to mix by invert-
ing the cuvet gently and
slowly for 50 seconds, while
taking care not to induce
air bubbles. A deposit re-
mains, but this does not
affect the measurement. Time and way
of shaking could sensitively affect the
measurement.
• Reinsert the cuvet into the instrument,
taking care not to shake it.
• Press TIMER 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 blink during mea-
surement.
• The instrument directly displays concentration in mg/L of nitrate-
nitrogen (NO
3
-N) 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
Iron(III) (positive interference)
Strong oxidizing and reducing substances
Sulfide (it must be absent)