Hanna Instruments HI 96711 - Manual (Page 10)

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The reading should be within specifications as reported in the CAL CHECK TM Standard
Certificate. If the value is found out of the specifications, please check that the cuvettes are free
of fingerprints, oil or dirt and repeat validation. If results are still found out of specifications,
then recalibrate the instrument.
• Press ZERO/CFM and the lamp, cuvette
and detector icons will appear on the
display, depending on the measurement
phase.
• After a few seconds, the display will
show “-0.0-”. The meter is now zeroed
and ready for validation.
• Remove the cuvette.
• Place the specific CAL CHECK TM Standard
Cuvette B into the cuvette holder, for:
Free Chlorine:
B, HI 96701-11
or
Total Chlorine: B, HI 96711-11
Ensure that the notch on the cap is
positioned securely into the groove.
• Press CAL CHECK TM and the lamp, cuvette
and detector icons together with “CAL
CHECK”
will appear on the display,
depending on the measurement phase.
• At the end of the measurement the display
will show the validation standard value.
• At the end of measurement, the instrument
directly displays concentration in mg/L of
free or total chlorine and the range
number on the LCD.
INTERFERENCES
Bromine (positive error)
Oxidized Manganese and Chromium (positive error)
Chlorine dioxide (positive error) Ozone (positive error)
Iodine (positive error)
In case of water 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.
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.
VALIDATION PROCEDURE
Use the validation procedure to ensure that the instrument is properly calibrated.
Warning:
Do not validate the instrument with any standard solutions other than the HANNA CAL
CHECK TM Standards, otherwise erroneous results will be obtained.
Note: The validation is performed only for the selected parameter. For full validation of the
instrument, the following procedure must be performed for each parameter.
• Turn the meter on by pressing ON/OFF.
• When the beeper sounds briefly and the
LCD displays dashes, the meter is ready.
• Place the CAL CHECK TM Standard
Cuvette A into the cuvette holder and
ensure that the notch on the cap is
positioned securely into the groove.