1 5
error). To resolve this, neutralize the sample with
diluted HCl.
• Acidity:
above 150 mg/L CaCO
3
. May not be reliably
develop the full amout of color or it may rapidly
fade (negative error). To resolve this, neutralize
the sample with diluted NaOH.
• Hardness:
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.
• Bromine (Br
2
):
positive error.
• Chloride dioxide (ClO
2
):
positive error.
• Ozone (O
3
):
positive error.
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.
•
Turn the meter on by pressing
ON/OFF
.
• Press
ZERO/CFM
and the lamp, cuvet
and detector icons will appear on the
display, depending on the measurement
phase.
• Place the
CAL CHECK
TM
Standard
HI 95761-11
Cuvet A into the cuvet
holder and ensure that the notch on the
cap is positioned securely into the groove.
• When the beeper sounds briefly and the
LCD displays dashes, the meter is ready.