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 dis-
play lights up. At start-up, all the LCD segments
are displayed for 1 second, then the percent in-
dication of the remaining battery life is shown for
another 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 equiva-
lent to the pH.
To freeze the display
While in measurement mode, press the SET/
HOLD button until HOLD appears on the sec-
ondary 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
signal 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 sec-
ondary display.
OPERATIONAL GUIDE
• 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 thor-
oughly 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 se-
lected). After 1 second the meter activates the
automatic buffer recognition feature. If a valid
buffer is detected, 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
accepts the calibration when the measure-
ment is stable; the meter will show on the
primary display the accepted buffer, with the
message “OK 1” on the secondary display,
and an audible signal is produced. After 1 sec-
ond, 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 normal measuring mode. After the button
is pressed, the meter shows "7.01" (or "6.86")
- "OK 1", and an audible signal is produced.
pH MEASUREMENT & CALIBRATION
Setup mode allows the selection of the tem-
perature unit and of the pH buffer set.
To enter the Setup mode, press and hold the
ON/OFF/MODE button until CAL on the sec-
ondary display is replaced by TEMP and the
current temperature unit (E.g. TEMP °C). Then:
•
for °C/°F selection
, use SET/HOLD. 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 return 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 SET/
HOLD, then press ON/OFF/MODE to return
to normal mode.
METER SETUP
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 con-
dition. 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. Reat-
tach the back making sure that the gasket is
in place and tighten the 4 screws.
BATTERY REPLACEMENT
• 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.
ORP MEASUREMENT
SENSOR CHECK
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
electrode is considered "poor", and it is recom-
mended to replace it with a new one.
Note: Always recalibrate the meter after replac-
ing the electrode.
After 1 second, the meter automatically returns
to 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 recog-
nized. 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 pro-
cedure. When the buffer is accepted, the LCD
shows the accepted value with the “OK 2”
message on the secondary display. The meter
then returns to the normal 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 sec-
ond and the meter returns to normal mode.
• To reset to the default values and clear a pre-
vious 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 be-
fore measuring the offset and the slope.