14
• Alternatively, wait for 3 minutes then just
press
READ/ /TIMER.
In all cases, the
lamp, cuvette and detector icons will
appear on the display, depending on the
measurement phase.
• At the end of measurement, the instrument
directly displays concentration in mg/L of
nitrate-nitrogen on the LCD.
• To convert the reading to mg/L of nitrate
(NO
3
-
), multiply by the factor 4.43.
INTERFERENCES:
Interference may be caused by:
Ammonia and amines, as urea and primary aliphatic amines. Chloride above 100 mg/L (negative
interference). Chlorine above 2 mg/L (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, preform the tests at room temperature, between 18 °C and 28
°C (65 °F to 83 °F).
For best result
: Intensely colored samples or suspended matter in large amounts will cause
interference. Therefore sample should be adequately treated before performing the test.