Hanna Instruments HI 991001 - Manual (Page 2)

To connect the probe
With the meter turned off, connect the HI 1296D
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 and check the bat-
tery status
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 freeze the display
While in measurement mode, press the SET/
HOLD button, HOLD appears on the secondary
display and 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 METER SETUP pH MEASUREMENT & CALIBRATION
BATTERY REPLACEMENT
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 second-
ary display is replaced by TEMP and the current
temperature 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
selection mode; press ON/OFF/MODE twice
to return to the normal measuring mode.
• to change the calibration buffer set, after set-
ting 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 but-
ton, then press ON/OFF/MODE to return to nor-
mal mode.
• 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.
• Place the tip of 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) on the primary
LCD, while the secondary LCD shows 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
For better accuracy, frequent calibration of the
instrument is recommended. In addition, the
instrument must be recalibrated whenever:
a) The pH electrode is replaced.
b) After testing aggressive chemicals.
c) Where high accuracy is required.
d) At least once a month.
• From normal mode, press and hold ON/OFF/
MODE until OFF on the secondary display is
replaced by CAL. Release the button.
• The LCD enters the calibration mode, display-
ing “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 rec-
ognition feature. If a valid buffer is detected,
then its value is shown on the primary display,
and REC appears on the secondary LCD. If
no valid buffer is detected, the meter keeps
the USE indication active for 12 seconds, and
then 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 reading is
stable; the meter will show on the primary dis-
play 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 measuring 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.
After 1 second, the meter automatically returns
to the normal measuring mode.
Note: It is always recommended to carry out a
two-point calibration for better accuracy.
• 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 de-
fault values
• 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.
The meter displays the remaining battery
percentage when turned on. When the level
is below 5%, the
symbol on the bottom
left of the LCD blinks to indicate a low battery
condition. If the battery level is low enough to
cause erroneous readings, the Battery Error
Prevention System (BEPS) turns the meter
off.
Unscrew the 4 screws located on the back
of the meter and carefully replace the 3 AA
batteries 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 to ensure
a watertight seal.