Hanna Instruments HI 83208-2008 - Manual (Page 12)

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• Reinsert the cuvette into the instrument.
• Press READ to start the reading.
• The instrument displays the results in mg/L of free chlorine.
INTERFERENCES
Interference may be caused by: Bromine, Iodine, Ozone, Oxidized forms of Chromium and Manganese.
In case of water with hardness greater than 500 mg/L CaCO
3
, shake the sample for approximately 2
minutes after adding the powder reagent.
In case of water with alkalinity greater than 250 mg/L CaCO
3
or acidity greater than 150 mg/L CaCO
3
,
the color of the sample may develop only partially, or may rapidly fade. To resolve this, neutralize the
sample with diluted HCl or NaOH.
Free Chlorine Free Chlorine
• Press ZERO key. The meter will show “-0.0-” when the meter is zeroed and ready for measurement.
• Remove the cuvette.
Powder reagents procedure
• Add the content of one packet of HI 93701-0 DPD reagent.
Replace the cap and shake gently for 20 seconds (or 2 minutes for
seawater analysis).
• Wait for a minute to allow the undissolved reagent to settle and
reinsert the cuvette into the instrument.
• Press TIMER and the display will show the countdown prior to the measurement or, alternatively, wait
for 1 minute and press READ. When the timer ends the meter will perform the reading. The instrument
displays the results in mg/L of free chlorine.
Liquid reagents procedure
• To an empty cuvette add 3 drops of HI 93701A-F DPD1
indicator and 3 drops of HI 93701B-F DPD1 buffer. Swirl
gently to mix, and immediately add 10 mL of unreacted
sample. Replace the cap and shake gently again.
x 3 x 3