Hanna Instruments hi 991003 Manuel D’Utilisation

To connect the probe
With the meter turned off, connect the HI 1297D
probe to the DIN socket on the top of the meter by
aligning the pins and pushing in the plug. Tighten
the nut to ensure a good connection. Remove the
protective cap from the probe before taking any
measurements.
To turn the meter ON
Press the ON/OFF/MODE button until the display
lights up. At start-up, all the LCD segments are
displayed for 1 second, then the percent indica-
tion of the remaining battery life is shown for an-
other second (E.g. % 100 BATT). The meter then
enters the normal measuring mode.
Note: If the display needs to be checked, keep the

ON button pressed while turning the meter on.
The meter will display all segments as long as
the button is pressed.

To select the measurement range
While in normal measurement mode, press the
SET/HOLD button to select pH, pH-mV or ORP
(mV) measurement range.
Note: “pH-mV” indicates the mV value equivalent

to the pH.

To freeze the display
While in measurement mode, press the SET/
HOLD button until HOLD appears on the second-
ary display; the reading will be frozen on the LCD
(E.g. pH 5.73 HOLD). Press any button to return to
normal mode.
To turn the meter OFF
While in normal measurement mode, press the
ON/OFF/MODE button. OFF will appear on the
secondary display. Release the button.
Note: the meter is provided with an acoustic sig-

nal feature, which can be disabled using the
switch located in the battery compartment.

Note: When the meter detects the absence of a

temperature probe at its input, the Automatic
Temperature Compensation is turned off, and
the meter uses a default value of 25°C (77°F)
for the temperature measurement and com-
pensation. In this condition, the secondary LCD
shows 25.0°C (77.0°F) blinking. When a probe
is connected, the meter automatically returns
to the ATC mode, the ATC tag is turned on, and
the temperature is shown on the secondary
display.

• Make sure the meter has been calibrated be-

fore use.

• If the probe is dry, soak it in HI 70300 storage

solution for one hour to reactivate it.

• Set the meter to pH range.
• Place the probe into the sample to be tested.
• Stir briefly and wait until the 

 symbol on the top

left of the LCD is turned off.

• The LCD shows the pH value (automatically

compensated for temperature) and the tem-
perature of the solution.

• If measurements are taken in different samples

successively, rinse the probe tip thoroughly to
eliminate cross-contamination. After cleaning,
rinse the probe tip with some of the sample to
be measured.

pH calibration
• Press and hold the ON/OFF/MODE button until

OFF on the secondary display is replaced by
CAL.

• Release the button. The LCD enters the cali-

bration mode, displaying “pH 7.01 USE” (or “pH
6.86 USE” if the NIST buffer set was selected).
After 1 second the meter activates the automatic
buffer recognition feature. If a valid buffer is de-
tected, then its value is shown on the primary
display, and REC appears on the secondary
display. If no valid buffer is detected, the meter
keeps the USE indication active for 12 seconds,
and then it replaces it with WRNG, indicating
that the sample being measured is not a valid
buffer.

• For a single-point calibration with buffers pH

4.01, 9.18 or 10.01, the meter automatically ac-
cepts the calibration when the measurement
is stable; the meter will show on the primary
display the accepted buffer, with the message
“OK 1” on the secondary display, and an au-
dible signal is produced. After 1 second, the
meter automatically returns to the normal mode.
If a single-point calibration with buffers pH 7.01
or 6.86 is desired, then after the calibration point
has been accepted the ON/OFF/MODE button
must be pressed in order to return to the nor-
mal measuring mode. After the button is
pressed, the meter shows "7.01" (or "6.86") -
"OK 1", and an audible signal is produced. After
1 second, the meter automatically returns to

Setup mode allows the selection of the tempera-
ture unit and of the pH buffer set.
To enter the Setup mode, press and hold the ON/
OFF/MODE button until CAL on the secondary dis-
play is replaced by TEMP and the current tempera-
ture unit (E.g. TEMP °C). Then:
• for °C/°F selection, use the SET/HOLD button.

After the temperature unit has been selected,
press ON/OFF/MODE to enter the buffer set se-
lection mode; press ON/OFF/MODE twice to re-
turn to the normal measuring mode.

• to change the calibration buffer set, after setting

the temperature unit, the meter will show the
current buffer set: “pH 7.01 BUFF” (for 4.01/7.01/
10.01) or “pH 6.86 BUFF” (for 4.01/6.86/9.18).
Change the set with the SET/HOLD button, then
press ON/OFF/MODE to return to normal mode.

The meter displays the remaining battery per-
centage when turned on. When the level is
below 5%, the 

-    +

 symbol on the bottom left of

the LCD blinks to indicate a low battery condi-
tion. If the battery level is low enough to cause
erroneous readings, the Battery Error Preven-
tion System (BEPS) turns the meter off.
Unscrew the 4 screws located on the back of
the meter and carefully replace the 3 AA bat-
teries located in the battery compartment, while
paying attention to their polarity. Reattach the
back making sure that the gasket is in place
and tighten the 4 screws.

• Make sure the probe is connected.
• Set the meter to ORP (mV) range.
• Place the probe into the sample to be tested,

stir briefly and wait until the 

 symbol on the top

left of the LCD is turned off.

• The meter will show the ORP (mV) value and

the temperature of the sample.

Note: The ORP range is factory calibrated.
Note: ATC tag turns off because the mV readings

are not temperature compensated.

The Sensor Check feature allows the user to
check the electrode status at any time. This is
possible by setting the meter to pH-mV range.
The offset value is the reading of the electrode
immersed in pH7 buffer 

(@25°C/77°F)

. If this read-

ing is outside the range ±40 mV, the electrode is
considered "poor" and it is recommended to re-
place it with a new one.
The slope value of the electrode is the difference
between readings in pH7 and in pH4 buffers. For
a new electrode this is about 174 mV 

(@25°C/

77°F)

. With time, the slope value decreases. When

it reaches the value of about 150 mV, the elec-
trode is considered "poor", and it is recommended
to replace it with a new one.
Note: Always recalibrate the meter after replacing

the electrode.

the normal measuring mode.

• For a two-point calibration, place the probe in

pH 7.01 (or pH 6.86) buffer. After the calibration
point has been accepted, the “pH 4.01 USE”
message appears. The message is held for
12 seconds, unless a valid buffer is recognized.
If no valid buffer is recognized, then the WRNG
message is shown. If a valid buffer (pH 4.01,
pH 10.01 or pH 9.18) is detected, then the meter
completes the calibration procedure. When the
buffer is accepted, the LCD shows the accepted
value with the “OK 2” message on the second-
ary display. The meter then returns to the nor-
mal measuring mode.

Note: When the calibration procedure is com-

pleted, the CAL tag is turned on.

To quit calibration and to reset to the default
• After entering the calibration mode and before

the first point is accepted, it is possible to quit
the procedure and return to the last calibration
data by pressing the ON/OFF/MODE button. The
secondary LCD displays ESC for 1 second and
the meter returns to normal mode.

• To reset to the default values and clear a previ-

ous calibration, press the SET/HOLD button
after entering the calibration mode and before
the first point is accepted.
The secondary LCD displays CLR for 1 sec-
ond, the meter resets to the default calibration
and the “CAL” tag on the LCD disappears.

Note: To ensure reliable readings, the electrode

must be cleaned with cleaning solution before
measuring the offset and the slope.