EUTECH INSTRUMENTS WATERPROOF CYBERSCAN DO 300 DISSOLVED OXYGEN... User manual

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Instruction Manual
DO 300
Waterproof Hand-held Dissolved Oxygen / Temperature Meter
68X248909
Rev 3 02/04

Preface
This manual serves to explain the use of the Waterproof DO 300 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 DO
300 meter as possible. If there are doubts in the use of the meter, please do not hesitate to contact
the nearest Authorised 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 subjected 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 © 2000.
Eutech Instruments Pte Ltd/ Oakton Instruments
All rights reserved.
Rev 3 02/04

TABLE OF CONTENTS
1INTRODUCTION 1
2DISPLAY AND KEYPAD FUNCTIONS 2
2.1 Display 2
2.2 Keypad 3
3PREPARATION 4
3.1 Inserting the Batteries 4
3.2 Connecting the Probe 5
4CALIBRATION 6
4.1 Preparing the meter for calibration 6
4.2 Temperature Calibration 7
4.3 Dissolved Oxygen Calibration in % Saturation 8
4.4 Dissolved Oxygen Calibration in mg/L (ppm) mode 10
5MEASUREMENT 11
5.1 Taking DO readings 11
5.2 Taking Pressure/Salinity Compensated DO measurements 13
6HOLD FUNCTION 14
7MEMORY FUNCTIONS 15
7.1 Memory Input 15
7.2 Memory Recall 16
8ADVANCED SETUP FUNCTIONS 17
8.1 Advanced SETUP Mode Detailed Overview 18
8.2 Clr: Memory Clear 20
8.3 dPr: Dissolved Oxygen Parameters 21
8.4 OFS: Offset for % Saturation Measurement 24
8.5 CAL: Previous Calibration Information 25
8.6 ELE: Electrode Properties 26
8.7 COF: Unit Configuration 28
8.8 LCd: Adjusting LCD Brightness 32
8.9 CLO: Setting the Real-Time Clock 33
8.10 rSt: Resetting to Factory Default Setting 35
9PROBE CARE AND MAINTENANCE 36
9.1 Probe Care 37
9.2 Membrane Housing Replacement 38
9.3 Membrane/O-ring Replacement (Optional Procedure) 39
9.4 Electrolyte Solution 41
9.5 DO Probe Troubleshooting Table 42
10 TROUBLE SHOOTING GUIDE 44
11 ERROR MESSAGES 45
12 SPECIFICATIONS 46
13 ACCESSORIES 47
14 DISSOLVED OXYGEN & METER THEORY 49
15 PRESSURE VS ALTITUDE TABLE 50
16 FACTORY DEFAULT SETTINGS 51
17 OVER-VIEW OF SETUP FUNCTIONS 52
18 WARRANTY 56
19 RETURN OF ITEMS 56

Instruction Manual DO 300
1
1 INTRODUCTION
Thank you for selecting the DO 300 waterproof portable meter. This meter is a
microprocessor-based instrument that is designed to be handy and capable of allowing one-
hand operation. It is capable of measuring Dissolved Oxygen in mg/L or ppm, % Saturation of
Oxygen and Temperature. 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 dissolved oxygen / temperature
probe with submersible cable (inclusive maintenance kit), instruction manual, and a warranty
card. Please read this manual thoroughly before operating your meter.
Figure 1: Waterproof DO 300 Dissolved Oxygen Meter

Instruction Manual DO 300
2
2 DISPLAY AND KEYPAD FUNCTIONS
2.1 Display
The LCD has a primary and secondary display.
oThe primary display shows the measured DO value either in mg/L, ppm or %,
depending on units of measurement selected.
oThe secondary display shows the measured temperature in °C.
The display also shows error messages, keypad functions and program functions. See Figure
2.
Figure 2: Full LCD Screen
1. SETUP mode indicator 8. Temperature indicator 14. Probe indicator
2. MEASurement mode indicator 9. Automatic Temperature
Compensation indicator 15. Calibration indicator
3. CALibration indicator 10. Clock indicator 16. DO probe cell factor
4. MEMory recall mode indicator 11. ERRor indicator 17. Function ON / OFF
indicator
5. % saturation indicator 12. MEMory location indicator 18. HOLD indicator
6. ppt indicator for input of
Salinity value. 13. Low battery indicator 19. READY indicator
7. Oxygen solubility indicator in
mg/L or ppm.

Instruction Manual DO 300
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 1. Some buttons have several
functions depending on its mode of operation.
Key Function
ON/OFF Powers meter on and off. The meter powers on in the mode that you were last using.
For example, if you shut the meter off in mg/L measurement mode, the meter will be in
mg/L measurement mode when switched on. Note: The meter shuts off automatically
after 20 minutes of the last key press.
HOLD Freezes the measured reading. To activate, press HOLD while in measurement mode.
To release, press HOLD again.
NOTE: 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 1. Selects the measurement parameter. Press MODE to toggle between DO %
saturation; DO mg/L (or ppm) and date/time.
2. While in CAL mode under mg/L (or ppm) measurement status, this key will toggle
between mg/L (or ppm) calibration and temperature calibration (refer to section 4.2)
CAL/MEAS Toggles between Calibration and Measurement mode.
1. In DO % saturation measurement mode, press CAL/MEAS to enter DO %
saturation calibration mode.
2. In DO mg/L (or ppm) measurement mode, press CAL/MEAS to enter DO mg/L (or
ppm) calibration mode.
3. To abort calibration, press CAL/MEAS key again to go back to measurement
mode.
While in advanced SETUP mode: Press CAL/MEAS to return to main group menu from
sub group menus. Press CAL/MEAS again to return to measurement mode from main
menu.
ENTER 1. Press to confirm your calibration values in calibration mode.
2. While in SETUP mode, pressing the ENTER key confirms the main group menu
selection and takes you through each sub group menu.
MI/ &
MR/
In Measurement mode:
Press MI key to store the mg/L (ppm) or % Saturation values with its corresponding
temperature and date/time values, into the memory.
Press MR to retrieve data from memory in LIFO method.
In Calibration & Set up mode:
In DO mg/L (or ppm) and temperature calibration mode, press  or  keys to
increase or decrease the calibration values.
In SETUP mode, press  or  keys to scroll through the SETUP main group menu
and to set the parameters in the sub group menu.
SETUP Takes you into the SETUP mode. This mode lets you customise meter preference and
defaults, view calibration and electrode data.
LIGHT : Press to light up the backlit display.

Instruction Manual DO 300
4
3 PREPARATION
3.1 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 and secure into place using the two
screws removed earlier.
Figure 3: Back panel of meter showing meter compartment

Instruction Manual DO 300
5
3.2 Connecting the Probe
Your meter uses a dissolved oxygen/temperature probe. The probe cable has a notched 6-pin
connector to attach the probe to the meter.
NOTE: Do not substitute other probes. For a replacement probe, see the “Accessories”
section, page 47- 48.
NOTE: Keep connector dry and clean. Do not touch connector with soiled hands.
To connect the probe:
1. Line up the notch and 6 pins on the meter’s connector with the holes in the probe’s
connector. Push down and turn the locking ring to lock into place. See Figure 4 below.
2. To remove probe, unscrew the metal locking ring by turning the ring counterclockwise
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.
Figure 4: Connect DO Probe

Instruction Manual DO 300
6
4 CALIBRATION
4.1 Preparing the meter for calibration
The amount of oxygen dissolved in water will depend on its temperature, atmospheric
pressure and its salinity. While the pressure and salinity values are manually entered into the
instrument, the temperature is being measured by the probe. It is therefore very important that
the temperature is calibrated if necessary prior to the DO calibration.
The measurements of % Saturation of DO will linearly affect the measurement for DO in mg/L.
Hence calibration in % Saturation of DO should be carried out first.
Before calibrating your meter, make sure to rinse the probe well with DI (de-ionised) water or
rinse solution.
NOTE: Do not let membrane surface of the probe
touch any other surface. The probe guard (the piece
with holes fitted over the end of the probe) protects the
membrane; make sure this is always attached to the
probe while it is in use.
You can calibrate for dissolved oxygen in either %
saturation or mg/L (ppm). When you recalibrate your
meter in % saturation mode, old calibrations in %
saturation will be replaced while the % saturation offset
adjustment will be erased. However, recalibration in the
mg/L (ppm) concentration mode will only replace the old
calibration in the mg/L (ppm) mode and do not affect the calibration in the % saturation mode.
Before 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 mode last used (either in mg/L (ppm) or %
Saturation measurement mode or clock). For example, if you switch the meter off while it is in
the “mg/L” measurement mode, it will also be in the “mg/L” measurement mode when you
switch the meter on.
Figure 5: DO Probe guard

Instruction Manual DO 300
7
4.2 Temperature Calibration
DO in mg/L is dependent on temperature, so it is first necessary
to verify the temperature reading. Temperature calibration is
accessible from the mg/L or ppm measurement mode.
The built-in temperature sensor in the probe is factory calibrated.
Calibrate your sensor only if you suspect temperature errors may
have occurred over a long period of time or if you have a
replacement probe.
1. Dip the DO probe into a solution with known temperature.
Allow sufficient time for the temperature to stabilise.
NOTE: Use an accurate temperature meter or bath to determine
the solution’s temperature.
2. Ensure that the meter is in measurement mode. Press MODE
key if necessary to select mg/L mode.
3. Press CAL key to go into calibration mode of mg/L. The
primary display shows the measured DO in mg/L and the
secondary display shows the temperature.
4. Press MODE key to go into temperature offset adjustment
mode. The primary and secondary displays will show the
temperature values.
5. Press MI/or MR/key to set the correct temperature value.
NOTE: Temperature calibration is restricted to ± 5°C from the
factory default value displayed during calibration (shown in the
secondary display).
6. Press ENTER key to confirm the adjusted temperature.
NOTE: To exit from Temperature Calibration mode without
confirming calibration, DO NOT press ENTER in Step 6. Press
CAL/MEAS instead.
Since temperature readings affect the accuracy of the mg/L
measurements, it is strongly recommended to carry out a mg/L
calibration after a temperature calibration is done.
(The values shown above are for illustration purpose. Your meter may display different values depending on the settings &
your environmental conditions)

Instruction Manual DO 300
8
4.3 Dissolved Oxygen Calibration in % Saturation
You can calibrate this meter quickly and easily in air. The exact calibration value depends on
barometric pressure. The meter is set to a factory default of 760 mm Hg, which results in a
calibration value of 100% saturation in air.
NOTE: If the barometric pressure setting has been changed from
760 mm Hg, the calibration value in air will automatically adjust
to a value other than 100%. The adjusted value will be correct for
the new barometric pressure setting.
See page 21 to change the pressure setting. See Pressure vs
Altitude Table on page 50 for a table of adjusted % saturation
values.
To calibrate 100% Saturation:
1. Press MODE key to select % Saturation mode.
2. Rinse the probe well with deionised rinse water. For best
accuracy, wipe the end of the probe dry. Do not touch the
membrane.
3. Hold the probe in the air with the sensor facing down and
press CAL key to calibrate the meter. The LCD will show a
“CAL” mode. The primary display will show the current value
of measurement and the secondary display will show “100.0”
to which the meter is going to be calibrated. Wait for the
reading to stabilise.
4. Press ENTER key to confirm the calibration. The meter
automatically calibrates to 100% air saturation and returns to
the measurement mode.
NOTES:
Whenever an error occurs during calibration, the ERR indicator
appears in the lower left hand corner of the display.
You can offset your % DO calibration. See section 8.4 - OFS:
Offset for % Saturation Measurement on page 24 for directions.
Figure 6: To calibrate for
100% saturation

Instruction Manual DO 300
9
To calibrate 0% Saturation:
1. Rinse the probe well with DI rinse water. For best
accuracy, wipe the end of the probe dry. Do not touch the
membrane.
2. Press the MODE key to select the % saturation mode.
3. Place the probe in zero oxygen solution. Stir the solution
gently using the probe to homogenize the sample. Make
sure that the sample is continuously flowing past the
membrane sensor.
4. Press the CAL key. The CAL indicator will appear above
the primary display. The primary display will show the
factory default % saturation measurement and the
secondary display will show 0.0.
5. Wait for the reading to stabilise. If the READY indicator
feature is enabled, it will appear when the reading is
stable. (See section 8.7.1 on page 29 for Ready indicator
setup).
6. Press the ENTER key. The meter automatically calibrates
to 0.0% saturation and returns to Measurement mode.
See figure on right.
NOTE
The factory default % saturation measurement in step 4 must read at 10% or under for the
calibration to work correctly. Whenever an error occurs during calibration, the ERR indicator
appears in the lower left hand corner of the display.
Figure 7: To calibrate for
0.0% saturation
MEAS
%
%
%
ATC
°C
ATC
°C
8.5
23.4
CAL
MEAS
READY
23.4
ENTER
CAL
MEAS
READY

Instruction Manual DO 300
10
4.4 Dissolved Oxygen Calibration in mg/L (ppm) mode
Calibrating the meter to 100% in saturation mode will also calibrate the mg/L mode at the
value in mg/L corresponding to 100% saturation. This should produce acceptable results in
most applications.
This meter also lets you make a calibration adjustment in mg/L (ppm) mode without affecting
your % saturation calibration.
To select between mg/L and ppm units, see page 30.
To calibrate in mg/L (ppm) mode:
1. Calibrate 100% saturation as per Section 4.3.
2. Rinse the probe well with DI rinse water or rinse solution.
For best accuracy, wipe the end of the probe dry. Do not
touch the membrane.
3. Press the MODE key to select the mg/L (ppm) mode.
4. Dip the probe into a sample of known oxygen concentration.
Wait for the reading to stabilise. If the READY indicator
feature is enabled, it will appear when the reading is stable.
5. Press the CAL key. The CAL indicator will appear above the
primary display. The primary display will show the factory
default mg/L (ppm) measurement and the secondary
display shows the temperature.
6. Press the MI/or MR/keys to set the reading according
to the sample value.
7. Press the ENTER key. The meter automatically calibrates to
the value you entered and returns to Measurement mode.
Notes on mg/L (ppm) mode calibration
•During mg/L (ppm) measurement and calibration, the
meter adjusts to the barometric pressure value and the
salinity value that is programmed into the meter
•You can change the barometric pressure value and
salinity value in the mg/L (ppm) SETUP mode (see
section 8.3 on page 21 for directions).
•Whenever an error occurs during calibration, the ERR
indicator appears in the lower left hand corner of the
display.
Figure 8: To calibrate in
mg/L (ppm) mode
(The values shown above
are for illustration purpose.
Your meter may display
different values depending
on the settings & your
environmental conditions)

Instruction Manual DO 300
11
5 MEASUREMENT
5.1 Taking DO readings
During measurement, the probe can be:
zFully immersed in the solution
zPartially immersed in the solution
Do not allow the probe’s membrane surface to touch anything!
It is always advisable to insert the probe guard (refer to Figure
34 and 35 on pages 38 and 39)
IMPORTANT: Since the DO probe consumes oxygen from the
sample, the sample must constantly flow past the membrane
to achieve more accurate readings. You can use a stirrer to
accomplish this.
To take measurements:
1. Rinse the probe well with DI rinse water or rinse solution.
2. Select the appropriate measurement mode. Press the
MODE key to toggle between modes:
z% Saturation
zmg/L (or ppm)
zdate/time clock
3. Dip the probe into the sample. Stir the solution gently
using the probe to homogenise the sample. Make sure
that the sample is continuously flowing past the
membrane sensor.
4. Note the reading on the display. If the READY
indicator is switched on, it will appear when the reading
is stable.
5. You can press the (LIGHT) key to activate the backlit
LCD. This helps you read measurements in dimly lit areas.
Figure 9: Change
measurement mode
Figure 10: Taking
measurement

Instruction Manual DO 300
12
NOTE: To select between mg/L and ppm units, see Section 8.7.2 on page 30.
The ATC indicator should appear in the lower right hand corner of the display. If it does not,
this indicates an error.
Taking measurements with READY ON indicator selected on
If the READY indicator has been activated, the READY annunciator lights when the reading is
stable.
To enable or disable the READY indicator – see Section 8.7.1 on page 29 for directions.
Taking measurements with READY HOLD indicator selected on
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.
To enable or disable the Auto endpoint feature– see
Section 8.7.1 on page 29 for directions.
(The values shown above are for illustration purpose. Your meter may display
different values depending on the settings & your environmental conditions)
Figure 11 – Auto endpoint
feature

Instruction Manual DO 300
13
5.2 Taking Pressure/Salinity Compensated DO measurements
If necessary, you can adjust the pressure and salinity values of your measurements in the
SETUP mode. The DO meter will automatically compensate for salinity and pressure based on
the values entered in the SETUP functions. The meter is factory set at 760 mm Hg (101.3 kilo
Pascals) pressure adjustment and a factor of 0.0 ppt salinity adjustment. See Section 15 on
page 50 for a “Pressure vs Altitude” table.
Pressure Adjustment
1. Press the SETUP key to enter SETUP mode.
2. Press the MI/key once. The upper display shows “dPr”.
3. Press the ENTER key until the upper display shows a number and the lower display
shows “Hg” or “PA”.
4. Use the MI/and MR/keys to enter the barometric pressure. The upper display will
show the value you have entered.
5. Press ENTER to confirm pressure value.
6. Press CAL/MEAS to return to Measurement mode, or continue with step 5 on page 23 to
make a salinity adjustment [available from mg/L (ppm) SETUP mode only].
7. See Figure 18 on page 22.
Salinity Adjustment
NOTE: This mode appears in mg/L (or ppm) SETUP mode only.
1. Press the MODE key to select mg/L (ppm) mode.
2. Press the SETUP key to enter SETUP mode.
3. Press the MI/key once. The upper display shows “dPr”.
4. Press the ENTER key until the upper display shows a number and the lower display
shows “SAL”.
5. Use the MI/or MR/keys to enter the salinity of your solution in ppt. The upper
display will show the value you have entered. Salinity correction values from 0.0 to 50.0
ppt can be entered.
6. Press ENTER key to confirm value.
7. Press CAL/MEAS to return to Measurement mode.
8. See Figure 19 on page 23.

Instruction Manual DO 300
14
6 HOLD FUNCTION
This feature lets you freeze the dissolved oxygen and
temperature readings for a delayed observation.
HOLD can be used any time when in MEAS mode.
To hold a measurement, press the HOLD key while in
measurement mode. “HOLD” will appear on the
display.
To release the held value, press HOLD again.
Continue to take measurements.
NOTE: This meter shuts off automatically 20 minutes
after the last key pressed. If the meter is shut off either
automatically or manually, the HOLD value will be lost.
For longer storage, use the memory functions.
NOTE: This 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
Section 8.7.1 page 29.
(The values shown above are for illustration purpose. Your meter may display different values depending on the settings &
your environmental conditions)
Figure 12: HOLD feature

Instruction Manual DO 300
15
7 MEMORY FUNCTIONS
7.1 Memory Input
Your meter stores data in sets that include:
zDissolved oxygen with corresponding temperature
reading
zTime and date reading was taken
You can store up to 50 sets of data in any combination of %,
mg/L or ppm readings.
To store a reading:
1. During any measurement function (MEAS), press the MI
key to input any data into the memory.
2. MEM, “StO” and memory number will flash. The meter
then returns to measurement mode.
NOTE: If the memory is full, the first value stored will be
erased to create space for the new value.
Figure 13: Memory Input, First
Value
Figure 14: Memory Input,
Second Value
Figure 15: Memory Input,
Third Value

Instruction Manual DO 300
16
7.2 Memory Recall
This function recalls the previous readings stored in the
memory. You can only access MR from the MEASurement
mode. Memory recall is in “Last In First Out” order.
To recall readings:
1. Press the MR/key once to retrieve the last reading
stored. The memory location screen “MEM”, “LOC” and
the memory location number will be displayed.
2. Press the ENTER key to recall the reading stored under
that memory location number.
3. Press the ENTER key again to view the date and time
the reading was taken.
4. Press the ENTER key again to return to the “memory
location” screen. The display automatically moves to the
next memory location screen.
5. If necessary, use the MI/ or MR/key to scroll
through the memory location screen.
6. Repeat steps 2 to 5 to review additional stored data sets.
7. To exit Memory Recall, press the MEAS key to return to
the Measurement mode.
NOTES
Readings stored in memory are retained even if the unit is
turned off. To erase all readings stored in memory, use the
“Clr” function in the SETUP mode. See Section 8.2 on page 20.
(The values shown above are for illustration purpose. Your meter may display different values depending on the settings &
your environmental conditions)
Figure 16: Memory Recall
with Date and Time

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17
8 ADVANCED SETUP FUNCTIONS
Your waterproof meter advanced SETUP mode lets you customize your meter parameters. It’s
menu features different main groups for various parameter preferences.
This meter will have two sets of SETUP mode; one set is when SETUP mode is entered from
% saturation or Clock mode (% saturation SETUP mode) and the other set is when SETUP is
entered from the mg/L (ppm) measurement mode (mg/L (ppm) SETUP mode). In each set,
only main groups which are applicable to the measurement mode you are in when you enter
SETUP mode will be featured.
The full selections of available main groups are:
1. CLR: Memory clear
2. dPr: Dissolved Oxygen parameters
3. OFS: % saturation offset adjustment -- % saturation SETUP mode only
4. CAL: Calibration data
5. ELE: Probe data
6. COF: Configuration
7. LCd: Brightness of Backlit display
8. CLO: Clock setting
9. rSt: Reset meter to factory default
IMPORTANT: The main groups selection numbering will change accordingly with
respect to the two sets of SETUP mode.
See Section17 on page 52 for more a detailed overview on the different parameters available
in % saturation mode and mg/L (ppm) mode.