Hanna Instruments HI 8424 User manual

Instruction Manual
HI8424
Portable pH/mV/°C Meter
www.hannainst.com

2
TABLE OF CONTENTS
PRELIMINARY EXAMINATION .......................................................................3
GENERAL DESCRIPTION................................................................................3
FUNCTIONAL DESCRIPTION ..........................................................................4
SPECIFICATIONS .........................................................................................5
OPERATIONAL GUIDE...................................................................................6
pH CALIBRATION .........................................................................................9
pH BUFFER TEMPERATURE DEPENDENCE ....................................................11
MENU SELECTION......................................................................................12
mV CALIBRATION ......................................................................................13
TEMPERATURE CALIBRATION .....................................................................13
BATTERY REPLACEMENT .............................................................................14
LCD MESSAGES AND TROUBLESHOOTING ....................................................15
ELECTRODE CONDITIONING & MAINTENANCE...............................................17
ACCESSORIES............................................................................................19
pH ELECTRODE APPLICATION REFERENCE GUIDE ..........................................25
Dear Customer,
Thank you for choosing a Hanna Instruments Product.
Please read this instruction manual carefully before using this instrument. This manual
will provide you with the necessary information for the correct use of this instru-
ment, as well as a precise idea of its versatility.
If you need additional technical information, do not hesitate to e-mail us at
[email protected] or view our worldwide contact list at www.hannainst.
com.

3
Remove the instrument from the packing material and examine it carefully to make
sure that no damage has occurred during shipment. If there is any damage, please
contact your local Hanna Instruments Office.
The meter is supplied complete with:
• HI1230B pH electrode
• HI7662 temperature probe
• pH 4.01 & pH 7.01 buffer solutions, 20 mL each
• HI700661 cleaning solution, 20 mL sachet (2 pcs.)
• 9V battery
• Instruction manual
Note: Save all packing material until you are sure that the instrument functions
correctly. Any defective items must be returned in the original packing
with the supplied accessories.
HI8424 is a portable microprocessor-based pH/mV/temperature meter.
It features an enhanced user interface, rainproof casing, battery percentage
indication, low battery detection, automatic shut-off, automatic calibration and
error codes to guide the user in calibration and troubleshooting.
The pH calibration procedure automatically recognizes three memorized buffer
values: pH 4.01, 7.01 and 10.01.
This instrument can also measure ORP. The resolution automatically switches from
0.1 mV to 1 mV when readings exceed ±699.9 mV.
The user can set the following parameters by entering the setup mode through
the keyboard:
• enabling or disabling the auto-off feature
• enabling or disabling the acoustic signal
• selecting the temperature unit, °C or °F
GENERAL DESCRIPTION
PRELIMINARY EXAMINATION

4
1) BNC connector for pH or ORP electrodes
2) Liquid Crystal Display (LCD)
3) RANGE key, to select pH, mV or temperature range
4) Up Arrow key, to manually set the temperature value when no temperature
probe is connected
5) CAL/SELECT key, to enter calibration mode or select menu options
6) CFM/SETUP key, to confirm data or enter/exit setup menu
7) Down Arrow key, to manually set the temperature value when no temperature
probe is connected
8) HOLD key, to freeze the reading on display
9) ON/OFF key, to switch the instrument ON or OFF
10)RCA socket for temperature probe
FUNCTIONAL DESCRIPTION

5
SPECIFICATIONS
Range
-2.00 to 16.00 pH
±699.9 mV/ ±1999 mV
-20.0 to 120.0 °C/ -4.0 to 248.0 °F
Resolution 0.01 pH/ 0.1 mV/ 1 mV/ 0.1 °C/ 0.1 °F
Accuracy
(@20 °C/68 °F) ±0.01 pH/ ±0.2 mV/ ±1 mV/ ±0.4 °C/ ±0.8 °F
Typical EMC
Deviation ±0.02 pH/ ±0.2 mV/ ±1 mV/ ±0.4 °C/ ±0.8 °F
pH Calibration
Automatic, 1 or 2 point, with 3 memorized buffer values
(pH 4.01, 7.01, 10.01)
Offset: ±1 pH; Slope: from 75 to 110%
Temperature
Compensation
Automatic, -20 to 120 °C (-4 to 248 °F) or manual
without temperature probe
Probes (included) HI1230B double junction, gel-filled pH electrode
HI7662 temperature probe
Battery Type 9V (1 pc.)
Battery Life Approx. 150 hours of continuous use
Auto-off After 20 minutes of non-use or disabled
(user-selectable)
Environment 0 to 50 °C (32 to 122 °F); RH max 100%
Dimensions 164 x 76 x 45 mm (6.5 x 3.0 x 1.8”)
Weight 180 g (6.3 oz.)

6
INITIAL PREPARATION
• Remove the electrode protective cap before taking any measurements. If the
electrode has been left dry, soak the tip in HI70300 storage solution for a few
hours or overnight to reactivate it.
• Connect the pH electrode to the BNC connector on the top of the instrument.
• Connect the temperature probe to the RCA connector. The temperature probe can
be used independently to take temperature measurements, or in conjunction
with the pH electrode to utilize the ATC capability of the meter.
• Turn the meter ON by pressing the ON/OFF key. The display shows all the
used segments for a few seconds (or as long as the button is held), followed
by the percentage indication of the remaining battery life, and then enters
normal measurement mode.
pH MEASUREMENTS
• To take a pH measurement simply submerge
the electrode tip (at least 4 cm/1½”) and the
temperature probe into the sample to be tested.
• Select the pH mode by pressing the RANGE key
until the display changes to pH.
• Stir gently and wait for the stability symbol (hourglass) to turn off. The display
will show the pH value automatically compensated for temperature.
Notes:
• In order to take accurate pH measurements, make sure that the instrument
has been calibrated before use (see page 9).
• If measurements are taken in different samples successively, it is recommended
to rinse the electrode thoroughly to avoid cross-contamination. After cleaning, it
is recommended to rinse the electrode with some of the sample to be measured.
OPERATIONAL GUIDE

7
TEMPERATURE COMPENSATION
The meter is designed to compensate for temperature, as the response of the pH
electrode is directly affected by temperature.
Automatic Temperature Compensation (ATC shown on LCD)
To use the ATC feature, submerge the temperature probe into the sample as close
as possible to the electrode and wait for a few minutes. The displayed pH reading
is compensated for the temperature of the sample.
Manual Temperature Compensation (MTC shown on LCD)
If the temperature probe is not connected, it is possible to enter the temperature
value manually.
• Record the sample temperature by using a ChecktempC (if you are measur-
ing temperature in °C, or ChecktempF for °F readings) or another accurate
thermometer.
• Press RANGE to select the temperature mode. The “°C” (or “°F”) symbol will
blink to indicate that the temperature probe is not connected.
•Use the UP and DOWN keys to display and set
the sample temperature (e.g. 25 °C).
• Press RANGE to select the pH measurement mode and immerse the electrode
into the sample. The displayed pH reading will be temperature compensated
at the set value (in this case at 25 °C).
ORP MEASUREMENTS
Oxidation Reduction Potential (ORP) measurements provide a quantification of
the oxidizing or reducing power of the sample tested.
• Connect the ORP electrode (optional) to the BNC connector.
• To enter the “mV” mode turn the instrument ON and press the RANGE key
until the display changes to mV.
• Submerge the ORP electrode tip (at least 4 cm / 1½”) into the sample to be
tested and allow time for the reading to stabilize
(hourglass symbol turns off).
• Measurements within the ±699.9 mV range are
displayed with 0.1 mV resolution, while outside
this range the resolution is 1 mV.

8
Notes:
• To perform correct ORP measurements, the surface of the ORP electrode must
be clean and smooth.
• When not in use, the tip of the electrode should be kept moist (use HI70300
storage solution) and safe from any mechanical stress which might cause
damage to the glass/platinum junction.
TEMPERATURE MEASUREMENTS
• Turn the instrument ON and press the RANGE key to select the temperature
mode.
• Make sure the temperature probe is connected to the meter.
• Dip the temperature probe into the sample, allow the reading to stabilize
(hourglass symbol turns off) and read the temperature value.
• Temperature measurements can be displayed in °C or °F units (see “Menu
selection” for details).
Notes:
• A blinking full scale value means that the reading is out of range.
•To freeze a reading on display while in measure-
ment mode, press the HOLD key. The “HOLD” tag
will blink. The pH, mV and temperature values
are held, and the RANGE key can be used to
view the values. Press HOLD again to return to
normal mode.
• If enabled, keypresses are followed with an acoustic signal. A lower note
indicates that the key is not currently active.
• To save battery life, the meter is provided with an auto-off feature, which
turns the instrument off after 20 minutes of non-use. This feature can be
disabled by the user (see “Menu selection” for details).

9
pH CALIBRATION
For better accuracy, frequent calibration of the instrument is recommended.
The instrument should be recalibrated for pH:
a) Whenever the pH electrode or temperature probe is replaced
b) At least once a week
c) After testing aggressive chemicals
d) When extreme accuracy is required
PREPARATION
Pour small quantities of pH 7.01 (HI7007) and pH 4.01 (HI7004) or pH 10.01
(HI7010) buffer solutions into two clean beakers.
For accurate calibration use two beakers for each buffer solution, one for rins-
ing the electrode tip, and one for calibration. In this way contamination of the
buffers is minimized.
For measurements in acidic samples, it is recommended to calibrate the meter
by using pH 7.01 (HI7007) and pH 4.01 (HI7004) buffers, while for alkaline
measurements use pH 7.01 (HI7007) and pH 10.01 (HI7010) buffers.
PROCEDURE
• Connect the pH electrode and the temperature probe, then switch the meter
ON.
• Remove the electrode protective cap, rinse the electrode
tip with pH 7.01 solution, then immerse the pH electrode
and temperature probe into pH 7.01 buffer solution;
stir gently and wait a few minutes for the electrode to
stabilize and reach thermal equilibrium.
Note: The electrode should be submerged approximately 4 cm
(1½”) into the solution. The temperature probe should
be located close to the pH electrode.
• Press RANGE to display pH measurement.
• Press CAL to enter the calibration mode. The buffer value @25 °C (77 °F)
and the “pH” symbol will blink on the display.
•The meter expects a pH 7.01 buffer.

10
•When the buffer value is recognized and the
reading is stable, an acoustic signal (if enabled)
advises the user, the “pH” symbol stops flash-
ing, the hourglass indicator disappears and the
“CFM” tag starts blinking to indicate that the
value can be confirmed.
•Press CFM to store the first calibration point.
•The meter expects a pH 4.01 or 10.01 buffer.
•Rinse and immerse the pH electrode and the
temperature probe in pH 4.01 or pH 10.01
buffer (2nd calibration point) and stir gently.
•When the buffer value is recognized and the
reading is stable, an acoustic signal (if enabled)
advises the user, the “pH” symbol stops flash-
ing, the hourglass indicator disappears and the
“CFM” tag starts blinking to indicate that the
value can be confirmed.
•Press CFM to store the second calibration point.
•The meter returns to normal mode.
The pH calibration is now complete; “CAL” and
the pH tags corresponding to the buffers used for
calibration are lit on the LCD.
Notes:
• If the buffer value is not recognized, after 12 seconds the meter will display
blinking dashes together with the “WRONG”
tag. Either the buffer solution is wrong or out
of specification and needs to be replaced or the
electrode is damaged.
• The meter will retain the calibration if the battery is removed.
• To quit calibration and keep previous data: press CAL after entering the
calibration mode and before the first point is accepted.
• To perform a single-point calibration: press CAL after the first point has been
confirmed.
If the temperature probe is not connected and manual temperature compensation
is required, follow the procedure below:
•Press RANGE to select the temperature mode.
•Rinse the pH electrode and place it into the pH 7.01 buffer, stir briefly and
wait a few minutes to reach thermal equilibrium.