8
1) Liquid Crystal Display
2) Cuvet Holder
3) Cuvet alignment indicator
4) ON/OFF key
5) ZERO/SET key
6) READ/TIMER key
7) CAL CHECK key
FUNCTIONAL DESCRIPTION
KEYPAD DESCRIPTION
• ON/OFF: to turn the meter on and off.
• ZERO/SET: this is a bi-functional key: press to zero the meter prior to measurement, or hold
the key for 3 seconds to select the desired parameter (“701” chlorine LOW RANGE or “771”
chlorine ULTRA HIGH RANGE).
• READ/TIMER: this is a bi-functional key, just press for making a measurement, or hold the
key for 3 seconds to start a pre-programmed countdown prior to measurement.
• CAL CHECK: this bi-functional key allows to perform validation of the instrument just pressing
the CAL CHECK key, or hold the key for 3 seconds to enter the
calibration mode
.
OPERATING MODES
•
Measurement mode:
default operation mode, enables both
validation
and
measurement.
•
Calibration mode:
may be entered
by keeping CAL CHECK pressed for three seconds (the “CAL”
icon appears), it enables
calibration
of the instrument.
17
Use the validation procedure to ensure that the instrument is properly calibrated.
Warning
: do not validate or calibrate the instrument with standard solutions other than the Hanna
CAL CHECK™ Standards, otherwise erroneous results will be obtained.
For accurate Validation and Calibration results, please perform test at room temperature: 18 to 25°C
(64.5 to 77.0°F).
VALIDATION PROCEDURE
• Hold READ/TIMER for three seconds. The
display will show the countdown prior to
measurement.
Alternatively, wait for 1 minute and just
press READ/TIMER.
In both cases “SIP” will blink during
measurement.
• The instrument directly displays concentration
in mg/L of free chlorine on the Liquid
Crystal Display.
or
INTERFERENCES
• Alkalinity:
• Acidity:
• Hardness:
• Bromine (Br
2
):
• Iodine (I
2
):
above 1,000 mg/L CaCO
3
if present as bicarbonate (HCO
3
-
, sample pH < 8.3);
above 250 mg/L CaCO
3
if present as carbonate (CO
3
2-
, sample pH > 9.0).
In both cases, it will not reliably develop the full amount of color or it may rapidly
fade (negative error). To resolve this, neutralize the sample with diluted HCl.
above 150 mg/L CaCO
3
. May not reliably develop the full amount of color or it
may rapidly fade (negative error). To resolve this, neutralize the sample with
diluted 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.
positive error.
positive error.
• Chlorine dioxide (ClO
2
):
positive error.
• Ozone (O
3
):
• Oxidized Manganese
and Chromium:
positive error.
positive error.
Temperature correction for Validation: corrected value = read value
×
[1
+
0.002
×
(20
−
T(°C))]
corrected value = read value
×
[1
+
0.001
×
(68
−
T(°F))]
