Hanna Instruments HI 93710 - Manual (Page 35)

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• Reinsert the cuvet into the instrument.
• Wait for approximately 30 seconds and then press READ. The
display will show “SIP” during measurement.
• The instrument directly displays concentration in mg/L of free
chlorine on the Liquid Crystal Display.
Note: Free and total chlorine have to be measured separately with
fresh unreacted samples following the above procedure if both
values are requested.
INTERFERENCES
Interference may be caused by:
Bromine
Iodine
Fluorine
Ozone
Oxidized manganese and Chromium
In case of water with hardness greater than 500 mg/L CaCO
3
, shake
the sample for approximately 1 minute after adding the 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 could
disappear or develop only partially. To resolve this, neutralize the
sample with diluted HCl or NaOH.
Free Chlorine