Oakton pH 300 User manual

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Instruction Manual
pH 300/310
Waterproof Hand-held pH / mV / Temperature Meter
68X248901
rev 5 11/02

Preface
This manual serves to explain the use of the waterproof pH 300/310 hand-held meter. It
functions in two ways, firstly as a step by step guide to help you to operate the meter.
Secondly, it serves as a handy reference guide. It is written to cover as many anticipated
applications of the waterproof pH 300/310 meter as possible. If there are doubts in the use of
the meter, please do not hesitate to contact the nearest Authorized Distributor.
Eutech Instruments/ Oakton Instruments cannot accept any responsibility for damage or
malfunction to the meter caused by improper use of the instrument.
The information presented in this manual is subject to change without notice as improvements
are made, and does not represent a commitment on the part of Eutech Instruments Pte Ltd/
Oakton Instruments.
Copyright © 1999
Eutech Instruments Pte Ltd/ Oakton Instruments
All rights reserved.
Rev 5, 11/02.

TABLE OF CONTENTS
1INTRODUCTION 1
2DISPLAY AND KEYPAD FUNCTIONS 2
2.1 Display 2
2.2 Keypad 3
2.3 Inserting the Batteries 4
2.4 Connecting the Electrode and Temperature Probe 5
2.5 Attaching the Electrode Holder to the Meter 7
2.6 Inserting the Electrode into the Electrode Holder 7
3CALIBRATION 8
3.1 Important Information on Meter Calibration 8
3.2 Preparing the Meter for Calibration 8
3.3 pH Calibration 10
3.4 Relative mV Calibration 12
3.5 Temperature Calibration 13
4MEASUREMENT 14
4.1 Automatic Temperature Compensation 14
4.2 Manual Temperature Compensation 15
4.3 Taking Measurements 16
5HOLD FUNCTION 17
6MEMORY FUNCTION 18
6.1 Memory Input 18
6.2 Memory Recall 19
7ADVANCED SETUP FUNCTIONS 21
7.1 Advanced SET-UP Mode Overview 23
7.2 P 1.0: Memory Clear (CLr) 25
7.3 P2.0: Viewing previous calibration data 26
7.4 P3.0: Viewing electrode data 27
7.5 P4.0: Unit configuration 29
7.6 P5.0: Resetting to factory default settings 34
7.7 P5.0: Setting the real-time clock 35
7.8 P6.0: Resetting to factory default settings 37
8PROBE CARE AND MAINTENANCE 38
9TROUBLE SHOOTING GUIDE 40
10 ERROR MESSAGES 41
11 SPECIFICATIONS 42
12 ACCESSORIES 43
13 ADDENDUM 1: METER FACTORY DEFAULT SETTINGS 46
14 WARRANTY 47
15 RETURN OF ITEMS 48

1
1 INTRODUCTION
Thank you for selecting this meter. The waterproof pH 300/310 Hand-held meter is a
microprocessor-based instrument that is designed to be handy and user-friendly. It is capable of
measuring pH, mV and temperature. It is designed to be handy and capable of allowing one-hand
operation. It is completely WATERPROOF --- and it FLOATS!
This meter has many user-friendly features – all of which are completely accessible through the
water-resistant membrane keypad. Your meter includes a temperature probe, two electrode holders,
batteries, instruction manual and a warranty card. Complete portable testing versions, including a
rugged carrying case and calibration solutions, are also available. Refer to the Accessories section
for more information.
Please read this manual thoroughly before operating your meter.

2
2 DISPLAY AND KEYPAD FUNCTIONS
2.1 Display
The LCD has a primary and secondary display.
•The primary display shows the measured pH, mV or Relative mV value.
•The secondary display shows the measured temperature.
The display also shows error messages, keypad functions and program functions.
See Figure 1.
SETUP MEAS CAL MEM
Primary Display
Secondary Display
R.mV
pH
MEM
ERR
AM PM
pH
ATC
°C °F
READY
HOLD
ON
OFF
-8.8.8.8
-1.8.8.8
1234
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Figure 1: Full LCD Screen
1. SETup mode indicator 7. Temperature indicator (°F
available on pH 310 meter
only)
13. Low battery indicator
2. MEASurement mode
indicator
8. pH buffer selection indicator 14. Probe indicator
3. CALibration indicator 9. Automatic Temperature
Compensation indicator
15. Buffer indicator
4. MEMory recall mode
indicator
10. Clock indicator (pH 310
meter only)
16. Function ON/OFF indicator
5. mV or Relative mV indicator 11. ERRor indicator 17. HOLD indicator
6. pH indicator 12. MEMory location indicator 18. READY indicator

3
2.2 Keypad
The large membrane keypad makes the instrument easy to use. Each button, when pressed, has a
corresponding graphic indicator on the LCD. See Figure 2. Some buttons have several functions
depending on its mode of operation.
Key Function
ON/OFF Powers on and shuts off the meter. When you switch on the meter, the meter starts up in the
mode that you last switched off from. For example, if you shut the meter off in mV
measurement mode, the meter will be in mV measurement mode when you switch the meter
on.
HOLD Freezes the measured reading. To activate, press HOLD while in measurement mode. To
release, press HOLD again.
pH 310 model only: When auto endpoint feature is switched on, it automatically holds reading
after 5 seconds of stability. The HOLD indicator appears on the display.
Press HOLD to release auto endpoint feature.
MODE Selects the measurement parameter. Press MODE to toggle between pH, mV (or relative mV)
and date/time [date/time feature available on pH 310 model only].
CAL/MEAS Toggles between Calibration and Measurement mode.
1. If you were in pH Measurement mode, press CAL/MEAS to enter pH Calibration mode.
NOTE: Temperature calibration is available from pH Calibration mode. See page 13 for
directions.
2. If you were in mV Measurement mode, press CAL/MEAS to enter mV Calibration mode.
While in SETUP main menu, pressing CAL/MEAS takes you out directly into the measurement
mode.
ENTER 1. To confirm your calibration values in Calibration mode.
2. To confirm selections in SETUP mode.
MI/▲&
MR/▼
In Measurement mode:
Press MI/▲(memory input) to store values with its corresponding temperature values in the
memory. Press MR/▼(memory recall) to retrieve data from memory.
In SETUP mode:
Press to scroll through the setup subgroup programs.
In mV calibration mode:
Press to adjust the calibration value.
SETUP Takes you into the SETUP mode. This mode lets you customize meter preference and
defaults, and view calibration and electrode offset data.
Figure 2 - Keypad

4
2.3 Inserting the Batteries
Four AAA batteries are included with your meter.
1. Use a Philips screwdriver to remove the two screws holding the battery cover. See Figure 3
below.
2. Remove battery cover to expose batteries.
3. Insert batteries. Follow the diagram inside the cover for correct polarity.
4. Replace the battery cover into its original position using the two screws removed earlier.
Figure 3 - Back panel of meter showing battery compartment

5
2.4 Connecting the Electrode and Temperature Probe
The waterproof pH 300/310 handheld pH meter uses any standard pH, ORP, or ISE electrode with a
BNC connector. For Automatic Temperature Compensation (ATC), this meter requires a
temperature probe with a special 6-pin connector.
Use either:
•All electrode with a BNC connector and a separate temperature probe with 6-pin connector
(EC-PHWPTEM-01W/ 35618-05).
•A “3-in-1” combination pH electrode with temperature probe designed specifically for pH 300
and pH 310 waterproof meters.
Refer to “Accessories” section on page 43 for more information on temperature probe and other
electrodes.
NOTE: Keep connectors dry and clean. Do not touch connector with soiled hands.
To connect the pH, ORP or ISE electrode:
1. Slide the BNC connector of the probe over the BNC connector socket on the meter. Make sure
the slots of the connector are in line with the posts of the socket. Rotate and push the
connector clockwise until it locks.
5. To remove electrode, push and rotate the connector counterclockwise. While holding onto the
metal part of the connector, pull it away from the meter.
CAUTION: Do not pull on the probe cord or the probe wires might disconnect.
To connect the temperature probe:
1. Line up the notch and 6 pins on the probe connector with the holes in the connector located on
the top of the meter. Push down and screw the metal sleeve to lock the probe connector into
place. See Figure 4.
6. To remove probe, unscrew the metal sleeve and slide up the probe connector. While holding
onto metal sleeve, pull probe away from the meter.
CAUTION: Do not pull on the probe cord or the probe wires might disconnect.

6
Figure 4 - Connection for pH Electrode (BNC) and Temperature probe (6-pin connector)

7
2.5 Attaching the Electrode Holder to the Meter
The waterproof pH 300/310 handheld meter comes complete with two
electrode holders. They are designed to facilitate one-hand operation.
Attach two electrode holders if you have a separate electrode and
temperature probe. Care must always be taken to avoid use of excessive
force in the process of attaching these components.
1. Locate the slot on the right-hand side of the meter.
2. Gently slide the flange of the
holder into the slot on the
meter. Make sure the holder is
secured properly into the slot.
See figure 5.
3. You can attach the electrode holder in different
positions. See figure 6.
To attach a second electrode holder:
4. Align the flange of the second electrode holder with
the slot of the first holder.
5. Slide the flange of the second holder into the slot of the
first holder until the tops of the holders are aligned and
secure. See figure 7.
2.6 Inserting the Electrode into the
Electrode Holder
Do not use excessive force when inserting electrodes into the
holders.
Insert the pH electrode into the opening of the first holder until
the top housing of the electrode touches the top of the holder.
If you are using a separate temperature probe, insert the probe into the opening of the second holder
until the ridge on the housing touches the top of the holder.
NOTE: The holder is designed for probes 12 mm in diameter. Electrodes larger than
12 mm may not fit in the holder. Forcing the electrode into the opening may
damage the holder or your electrode.
Figure 5 - Holder
slot into right-hand
side of meter
Figure 6 - Electrode can be placed in
different positions with holder
Figure 7 - Two holders

8
3 CALIBRATION
3.1 Important Information on Meter Calibration
When you re-calibrate your meter, old pH, Rel mV and mV calibration points are replaced on a point
by point basis. For example, if you previously calibrated your meter at pH 4.01, 7.00, and 10.01, and
you have now re-calibrated at pH 7.00, the meter retains the old calibration data at pH 4.01 and pH
10.01. To view current calibration points, see Program P2.0 in the SETUP section on page 26.
To completely re-calibrate your meter, or when you use a replacement probe, it is best to set the
meter to its factory defaults and re-calibrate the meter at all points. To reset the meter to its factory
defaults, see the SETUP section, Program P5.0, page 34 (for pH 300 meter) or Program P6.0, page
37 (for pH 310 meter).
3.2 Preparing the Meter for Calibration
Before starting calibration, make sure you are in the correct measurement mode. When you switch
on the meter, the meter starts up in the units last used. For example, if you shut the meter off in “mV”
units, the meter will read “mV” units when you switch the meter on.
Be sure to remove the protective electrode storage bottle or rubber cap of the electrode
before calibration or measurement. If the electrode has been stored dry, wet the electrode in tap
water for 10 minutes before calibrating or taking readings to saturate the pH electrode surface and
minimize drift.
Wash your electrode in deionized water after use, and store in electrode storage solution. If storage
solution is not available, use pH 4.01 or 7.00 buffer solution.
Do not reuse buffer solutions after calibration. Contaminants in the solution can affect the calibration,
and eventually the accuracy of the measurements. See page 43 for information on our high-quality
pH buffer solutions.

9
pH 300 meter calibration
The pH 300 meter is capable of up to 5-point pH calibration to ensure accuracy across the entire pH
range of the meter. Select from the following buffer options:
•USA buffers --- pH 1.68; 4.01, 7.00, 10.01, and 12.45.
The meter automatically recognizes and calibrates to these standard buffer values, which makes pH
calibration faster and easier.
pH 310 meter calibration
The pH 310 meter features three separate internationally-recognized buffer standards. Select the
buffer standard you require in SETUP mode Program 4.0 (see pages 27 & 34 for more information).
The pH 310 meter is capable of up to 6-point pH calibration, depending on the buffer standard
selection. Select from the following buffer options:
•USA buffers --- pH 1.68, 4.01, 7.00, 10.01, and 12.45.
•NIST buffers --- pH 1.68, 4.01, 6.86, 9.18, and 12.45.
•DIN buffers --- pH 1.09, 3.06, 4.65, 6.79, 9.23, and 12.75.
The meter automatically recognizes and calibrates to these standard buffer values, which makes pH
calibration faster and easier.

10
3.3 pH Calibration
NOTE: We recommend that you perform at least
2-point calibration using standard buffers
that bracket (one above and one below)
the expected sample range. You can
perform a 1-point calibration, but make
sure that the buffer value is close to the
sample value you are measuring.
1. If necessary, press the MODE key to select pH
mode. The pH indicator appears in the upper right
hand corner of the display.
2. Rinse the probe thoroughly with de-ionized water
or a rinse solution. Do not wipe the probe; this
causes a build-up of electrostatic charge on the
glass surface.
3. Dip the probe into the calibration buffer. The end
of the probe must be completely immersed into
the sample. Stir the probe gently to create a
homogeneous sample.
4. Press CAL/MEAS to enter pH calibration mode.
The CAL indicator will be shown. The primary
display will show the measured reading while the
smaller secondary display will indicate the pH
standard buffer solution.
5. Wait for the measured pH value to stabilize.
6. Press ENTER to confirm calibration. The meter is
now calibrated to the current buffer.
See figure 8.
Figure 8 - pH Calibration

11
7. Rinse the probe with de-ionized water or a rinse
solution, and place it in the next pH buffer.
8. Follow steps 5 and 6 for additional calibration
points. See Figure 9.
9. When all the calibration points as set in the Unit
Configuration Setup (see P4.2 on page 31) are
completed, the meter returns to Measurement
mode automatically. However, if you wish to
terminate the calibration without completing the
number of points as set in the Unit Configuration
Setup menu, press CAL/MEAS to return to pH
measurement mode.
NOTES:
To exit from pH calibration mode without confirming
calibration, DO NOT press ENTER in step 6. Press
CAL/MEAS instead.
If the selected buffer value is not within ±1.0 pH from the
measured pH value: the electrode and buffer icon blink
and the ERR annunciator appears in the lower left corner
of the display. Figure 10.
To limit the number of pH buffer values available during
calibration, see SETUP section P4.2 on page 31.
Figure 9 - Next point calibration for pH
4.01
Figure 10 - Err message and electrode
icon will appear if incorrect buffer are
used

12
3.4 Relative mV Calibration
1. While in the measurement function, press MODE to
enter the mV mode. The mV indicator appears in the
upper right hand corner. See figure at right.
2. Press the CAL/MEAS key. The CAL indicator
appears above the primary display. The primary
display shows the relative mV reading and the
secondary display shows the absolute mV value.
NOTE: If you have never calibrated relative mV or if
the meter has been reset, the value shown
in the primary display is the same as the
absolute mV value.
NOTE: “R.” annunciator will appear once mV
calibration is performed, an indication of
mV offset.
3. Press the MI/▲or MR/▼keys to enter the relative
mV value that matches your desired reading.
4. Press the ENTER key to confirm the reading and to
return to the measurement mode. The primary
display now shows the relative mV reading.
NOTES:
To view the mV offset value, use the SETUP mode
Program P3.1. See page 27 for instructions.
To reset all calibration and offset values in memory to the
factory default settings, use:
•In pH 300 meter: SETUP Program P 5.0. See page
34.
•In pH 310 meter: SETUP Program P 6.0. See page
37.
Fi
g
ure 11 - mV calibration

13
3.5 Temperature Calibration
The temperature sensor is factory calibrated. Calibrate the
temperature probe only if you suspect temperature errors that
may have occurred over a long period of time or if you have a
replacement probe.
Temperature Calibration
1. Make sure the ATC probe (or temperature connector of the
electrode) is attached to the 6-pin connector. The ATC
annunciator will appear at the right-hand side of the LCD.
2. Switch the meter on. Press the MODE key to select pH
mode.
3. Press the CAL/MEAS key to enter pH calibration mode.
The CAL indicator will appear above the primary display.
4. While in pH calibration mode, press the MODE key to enter
temperature calibration mode. The primary display shows
the temperature reading with last set offset and the
secondary display shows the factory default temperature
value.
5. Dip the ATC probe (or electrode) into a solution of known
temperature (i.e. a temperature bath). Allow time for the
temperature probe to stabilize.
6. Scroll with the MI/▲or MR/▼keys to set the correct
temperature value (i.e. the temperature of the temperature
bath). You can adjust the reading in increments of 0.1 °C.
7. Once you have selected the correct temperature, press the
ENTER key. The meter automatically returns to pH
measurement mode. See Figure 12.
NOTES:
•You can offset the temperature reading up to ±5°C from
original reading.
•To exit this program without confirming the temperature
calibration value, DO NOT press ENTER. Press
CAL/MEAS instead.
Figure 12 - Temperature
calibration

14
4 MEASUREMENT
This meter is capable of taking measurements with automatic or manual temperature compensation.
Automatic temperature compensation only occurs when a temperature sensor is plugged into the
meter. If there is no temperature sensor plugged into the meter, the default manual temperature
setting is automatically 25 °C. You can manually set the temperature to match your working
conditions using a separate thermometer.
4.1 Automatic Temperature Compensation
For automatic temperature compensation (ATC) simply plug
the temperature probe into the meter (see page 6 for
directions). The ATC indicator will light up on the LCD. See
figure 13.
NOTE: If you are using a temperature probe, the
probe must be submersed in the liquid you
are measuring.
Figure 13 - ATC annunciator will light
up when connected to temperature
probe

15
4.2 Manual Temperature
Compensation
IMPORTANT: For manual compensation, you must
disconnect the temperature probe (see page 6).
1. Switch the meter on. Press the MODE key to select
pH mode.
2. Press the CAL/MEAS key to enter pH calibration
mode. The CAL indicator will appear above the
primary display.
3. While in pH calibration mode, press the MODE key
to enter temperature calibration mode. The primary
display shows the current temperature setting and
the secondary display shows the default value 25
°C.
4. Check the temperature of your sample using an
accurate thermometer.
5. Press the MI/▲or MR/▼keys to set the
temperature to the measured value from step 4.
6. Press ENTER to confirm the selected temperature
and to return to the pH measurement mode.
See Figure 14.
The meter will now compensate pH readings for the
manually set temperature.
NOTES:
To exit this program without confirming the manual
temperature compensation value, DO NOT press ENTER
in step 6. Press CAL/MEAS instead.
Figure 14 - Manual temperature
compensation

16
4.3 Taking Measurements
Be sure to remove the electrode soaker bottle or
protective rubber cap on the electrode before
measurement.
To take readings:
1. Rinse the probe with de-ionized or distilled water
before use to remove any impurities adhering to the
probe body. If the pH electrode has dehydrated,
soak it for 30 minutes in electrode storage solution
or 2M – 4M KCl solution (sold separately).
2. Press ON to switch on meter. The MEAS
annunciator appears on the top center of the LCD. The ATC indicator appears in the lower
right-hand corner to indicator Automatic Temperature Compensation (see page 15 to set
Manual Temperature Compensation). See Figure 15.
3. Dip the probe into the sample.
When dipping the probe into the sample, the sensor or the glass bulb of the electrode must be
completely immersed into the sample. Stir the probe gently in the sample to create a homogeneous
sample.
4. Allow time for the reading to stabilize. Note the reading on the display.
5. To toggle between pH and mV (or Rel mV) readings, press the MODE key.
Taking measurements with READY indicator selected on
If the READY indicator has been activated, the READY annunciator lights when the reading is stable
*. Switch the READY indicator on or off in SETUP program P 4.1. See page 30 for directions.
* The READY indicator appears and the reading holds until the measured value exceeds the tolerance ( ± 0.02 pH; ±
0.8 mV <400;
± 1.2 mV > 400). Then, the READY annunciator turns off.
Taking measurements with the auto endpoint feature selected on
NOTE: This feature is available on model pH 310 only.
When a reading is stable for more than 5 seconds, the auto endpoint feature will automatically “hold”
the reading. The “hold” indicator appears on the left side of the display. Press the HOLD key to
release the reading. Switch the Auto endpoint feature on or off in SETUP program P 4.1, see page
30 for instructions.
Figure 15 - Measurement mode

17
5 HOLD FUNCTION
This feature lets you freeze the value of the pH, mV (or
Relative mV) and temperature readings for a delayed
observation. HOLD can be used any time when in MEAS
mode.
1. To hold a measurement, press the HOLD key while in
measurement mode. “HOLD” will appear on the
display. See Figure 16.
2. To release the held value, press HOLD again.
Continue to take measurements.
NOTE: This meter shuts off automatically 30 minutes after last key is pressed. If the meter is shut
off either automatically or manually, the HOLD value will be lost. For longer storage, use
the Memory functions described in page 18.
NOTE: for pH 310 model only: The pH 310 meter has an auto endpoint feature. When this feature
is switched on, the display will automatically “HOLD” a reading that has been stable for
more than 5 seconds. The “HOLD” indicator appears. Press the HOLD key to release the
reading. To switch on or off the auto endpoint feature, see SETUP Program P 4.1 on page
30.
Figure 16 - HOLD feature