USER MANUAL
MI 405
Ammonia Medium
Range Meter
Dear Customer,
Thank you for choosing a Martini product.
This manual will provide you with the
necessary information for the correct use of
the instrument.
Please read it carefully before using the
meter. This instrument is in compliance with
directives.
SPECIFICATIONS:
Range
0.00 to 9.99 mg/L (NH
3
-
N)
Resolution
0.01 mg/L
Precision
±0.10 mg/L @ 5.00 mg/L
Light Source
Blue LED 466 nm
Light Detector
Silicon Photocell and
466 nm narrow band interference filter
Method
Adaptation of Nessler method
Environment
0 to 50°C (32 to 122°F);
100% RH max.
Battery Type
1 x 9 volt
Auto-Shut off
After 10' of non-use
Dimensions
192 x 104 x 52 mm
(7.5 x 4.1 x 2”)
Weight
380 g
MEASUREMENT PROCEDURE:
1• Turn the meter on by pressing
ON/OFF.
2• When the LCD displays “- - -”, the
meter is ready.
3• Fill the cuvet with 10
mL of sample, up to the
mark, and replace the
cap.
4• Place the cuvet into the
holder and ensure that
the notch on the cap is
positioned securely into
the groove.
5• Press ZERO and “SIP”
will blink on the display.
6• After a few seconds the
display will show “-0.0-
”. The meter is now
zeroed and ready for
measurement.
7• Remove the cuvet. Open it.
8• Add 4 drops of NH3-1 (10 drops in
case of seawater analysis) and swirl
gently.
9• Add 4 drops of NH3-2 (10 drops in
case of seawater analysis). Replace
the cap and swirl gently.
10• Immediately reinsert
the cuvet into the
holder and ensure
that the notch on the
cap is positioned
securely into the
groove.
11• Press and hold
READ for 3 seconds
and the display will
show the countdown
prior to
the
measurement.
Alternatively, wait
for 3 minutes and 30
seconds and just press READ. In
both cases “SIP” will blink during
measurement.
12• The instrument directly displays the
concentration in mg/L of ammonia
nitrogen (NH3-N).
13• To convert the reading to mg/L of
ammonia (NH3), multiply by a factor
of 1.216.
Interferences
• Organic compounds like:
chloramines, various aliphatic and
aromatic amines, glycine, (positive
error).
To eliminate these interferences
distillation is required.
• Organic compounds like: aldehydes,
alcohols (e.g. ethanol) or acetone
(negative error).
To eliminate these interferences
distillation is required.
• Sulfide (S2-): may cause turbidity.
• Hardness above 1 g/L as Calcium
Carbonate (CaCO3).
