Oakton pH 5+ User manual

Instruction Manual
pH 5+ pH/°C
pH 6+ pH/°C/mV
Ion 6+ pH/°C/mV/Ion
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68X576801 Rev 0 07/2011

Table of Contents
1. INTRODUCTION......................................................................... 1
2. GETTING STARTED................................................................... 2
Description of Keypad Functions...............................................................................2
Description of LCD Annunciators ..............................................................................3
Inserting & Removing the Rubber Armor / Stand.......................................................4
Inserting New Batteries.............................................................................................4
Connecting Electrodes and Temperature Sensor......................................................5
Powering the Meter On.............................................................................................5
3. CALIBRATION............................................................................ 6
3.1 pH Calibration....................................................................................................6
pH Calibration Procedure...................................................................................7
Changing the pH Buffer Group...........................................................................8
Resetting User Calibrated Values ......................................................................9
3.2 Ion Calibration (Ion 6+ only).............................................................................10
Ion Calibration Procedure (Ion 6+ only)............................................................10
3.3 Millivolt (mV) Calibration (6+ only)....................................................................12
3.4 Temperature Calibration...................................................................................13
With Temperature Probe (Automatic Temperature Compensation)..................13
Without Temperature Probe (Manual Temperature Compensation).................14
4. MEASUREMENT ...................................................................... 15
Taking Measurements.............................................................................................15
Holding & Releasing a Reading ..............................................................................15
5. TROUBLESHOOTING.............................................................. 16
6. SPECIFICATIONS .................................................................... 17
7. REPLACEMENTS AND ACCESSORIES................................. 18
8. WARRANTY.............................................................................. 20
9. RETURN OF ITEMS.................................................................. 20

Instruction Manual pH 5+, pH 6+, Ion 6+
1. INTRODUCTION
Thank you for selecting our pH 5+, pH 6+, or Ion 6+ portable meter. This
microprocessor-based handheld instrument is both economical and easy to use.
The pH 5+ measures pH and temperature (oC).
The pH 6+ and Ion 6+ measure pH, mV (ORP) and temperature (oC).
The Ion 6+ can also measure direct ion concentration of various ions (mono and
divalent) using an ion selective electrodes (ISE). The mV mode is also useful for ISEs.
The 5+/6+ series meters advance our popular 5/6 series meters that were introduced in
1998.
Each meter includes alkaline “AAA” batteries, a rubber armor / stand, and instruction
manual. Please refer to Section—7 Replacements and Accessories for information
on additional accessories and calibration solutions.
We take great pride in every instrument we manufacture and hope this
one serves you well.
If you are viewing an electronic PDF version of this manual, look for bold and
underlined hyperlinks in the Table of Contents and elsewhere. Clicking on
them will immediately take you to the corresponding location in the manual.
*Find other helpful tips listed in grey boxes like this one!
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Instruction Manual pH 5+, pH 6+, Ion 6+
2. GETTING STARTED
Description of Keypad Functions
The pH 5+ and pH 6+ have four keys, while the Ion 6+ has six keys on its splash-proof
keypad as shown here:
Powers the meter on and off. Upon power on, the meter
automatically begins in the measurement mode that was last
used.
MODE: Selects measurement modes (pH, mV, Ion (Ion6+
only), & Temperature).
With meter off, press and hold or to access the 
(buffer),  (calibration), and  (electrode) setup menus
while powering on. Press or again to change setup
menus.
INCREMENT:(INC) for Temperature setting and calibration.
pH 5+ / pH 6+ Ion 6+
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Instruction Manual pH 5+, pH 6+, Ion 6+
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CALIBRATE: Press to begin calibration of the selected mode.
Press again during calibration to abort calibration and return to
measurement mode without confirming any values.
During setup mode, function is similar to “escape” or “go
back”, returning to the previous screen.
With meter off, press and hold to select the reset menu
() while powering on.
Increase value or scroll up in Setup or Cal modes.
Decrease value or scroll down in Setup or Cal modes.
HOLD: Freezes measured reading—indicated by “HO”. Press
again to resume live reading.
ENTER: Confirms values in calibration mode. Confirms
selections in setup mode.
Description of LCD Annunciators
The custom LCD consists of 3½-digit segments which uses annunciators for pH, mV or
oC (Temperature). No annunciator is shown in Ion mode. Other annunciators include
“HO” (when HOLD function is activated) and “LO” (low battery condition).

Instruction Manual pH 5+, pH 6+, Ion 6+
Inserting & Removing the Rubber Armor / Stand
Before removing the meter from the rubber armor, disconnect any electrodes. Push out
from the bottom edges of meter until it is completely out of boot.
To insert meter into the armor, slide in from the top of meter before pushing the bottom
edges of meter into position. Tilt the stand at the back of meter for table top usage as
desired.
Inserting New Batteries
The “LO” annunciator alerts you when battery power is running low. Power off the meter
before removing the batteries. After removing the rubber armor, push the battery cover
in the direction of the arrow and lift up—no screwdriver is required. Note the polarity of
batteries before inserting into position.
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Instruction Manual pH 5+, pH 6+, Ion 6+
5
Connecting Electrodes and Temperature Sensor
Align the BNC connector slots with the posts of meter’s socket and rotate connector
clockwise until it locks—do not force. To remove, rotate the connector in counter-
clockwise direction until it unlocks, and slide the connector off the socket. Insert the mini
phono jack of temperature sensor into the socket on the meter. Unplug the phono jack
to perform measurements without temperature compensation (25° C default).
2.5 mm Phono plug
for temperature
measurement
BNC connector of
pH, ORP, or Ion
Selective Electrode
Powering the Meter On
Press . All LCD segments will display momentarily during the self-diagnostic test,
before scrolling the model number, software revision, pH buffer group, and number of
pH calibration points selected before returning to the measurement mode:
If a temperature probe is not connected, either 25.0oC (factory default) or the last
calibrated temperature value is used. If a temperature probe is connected, the current
measured temperature is used.
Note: The Ion 6+ will display “ - - - ” in Ion concentration mode if the meter has not been
calibrated or if the meter has been reset. See Section 3—Ion Calibration.
“” (Over range) and “” (Under range) indicates the reading exceeds the maximum
or minimum measurement range. See Section 6—Specifications. However, the most
likely reason for these error messages is that the electrode is not connected or broken.

Instruction Manual pH 5+, pH 6+, Ion 6+
3. CALIBRATION
3.1 pH Calibration
The 5+ and 6+ meter is capable of calibrating up to 5 pH values using the USA or NIST
buffer groups, or 2 pH values using the Low Ionic buffer group. All new calibration
values will automatically override existing calibration data. The non-volatile memory will
retain calibration values upon power shut-off, and battery removal.
For best results, periodic calibration with known accurate standards is recommended.
Calibrate with standards that bracket your intended measuring range while including a
neutral standard (i.e. pH 7.00, 6.86, 6.97). For example, if you expect to measure
samples from pH 6.2 to pH 9.5, calibration using 4.01, 7.00, and 10.01 will work well.
To eliminate temperature errors associated with the pH electrode, attach the automatic
temperature compensation (ATC) probe for best accuracy. Without temperature
compensation, pH accuracy will worsen as samples deviate from 25 ºC and pH 7.
Always rinse electrodes with clean water before and after each calibration or
sample measurement to avoid cross-contamination.
The following calibration standards are automatically recognized;
Buffer Group Available pH Calibration Values
USA ()1.68, 4.01, 7.00*, 10.01, 12.45
NIST ()1.68, 4.01, 6.86*, 9.18, 12.45
Pb ()4.10, 6.97
*These are the only values suitable for a one-point calibration
See Section 3.1—Changing the pH Buffer Group to select a different buffer group.
Always use fresh pH buffer solutions for calibration. Do not reuse buffer solutions as
they change with prolonged exposure to air (especially pH 10 buffer) resulting in
decreased measurement accuracy. Promptly seal containers and store solutions in a
dark, dry, cool environment.
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Instruction Manual pH 5+, pH 6+, Ion 6+
pH Calibration Procedure
1. Turn on the meter and select pH mode by pressing if necessary.
2. Press to begin pH calibration mode. “” (calibrate) will display briefly. Notice
that the pH reading and “pH” annunciator will both blink.
3. Pour pH buffer calibration standard solution into a clean, dry container and dip your
pH electrode and temperature probe in the solution. Swirl gently or stir and wait for
reading to stabilize (approx. 30 seconds depending on your electrode condition).
4. When the pH reading has stabilized, the pH annunciator will stop blinking. Press
to confirm the value. “” (confirm) will display briefly. The pH value is
automatically adjusted to the buffer value shown from your selected buffer group.
The example below shows a successful pH 7.00 calibration at 25 °C.
5. For a one-point calibration with pH 7.00 or pH 6.86 only, press to return to
measurement mode. However for highest accuracy—perform a multiple-point
calibration. Repeat steps 3 & 4 with additional pH buffer calibration standards.
When you have completed the preset number of calibration points, the meter will
automatically save the calibration, cease blinking, and begin pH measurement.
Q: My meter, electrode & buffers are new—why does my pH 10 buffer read “10.06”?
A: Temperature influences pH. While pH 10 buffer is 10.00 at 25 °C / 77 °F, at
20 °C / 68 °F it is actually 10.06! This is why it is always best to record the temperature
as well as the pH reading!
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