EUTECH INSTRUMENTS CYBERSCAN DO 100 DISSOLVED OXYGEN METER User manual

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Instruction Manual
DO 100
Hand-held Dissolved Oxygen Meter
68X235201
rev 4 01/04

Preface
This manual serves to explain the use of the DO 100 hand-held meter. It functions as a step
by step guide to help you to operate the meter and as a handy reference guide. It is written to
cover as many anticipated applications of the DO 100 meter as possible. If there are doubts
in the use of this meter, please do not hesitate to contact the nearest Eutech
Instruments/Oakton Instruments 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 © 1998 All rights reserved.
Eutech Instruments Pte Ltd.
Oakton Instruments
Rev 4 01/04

TABLE OF CONTENTS
1INTRODUCTION 1
2DISPLAY AND KEYPAD FUNCTIONS 2
2.1 Display 2
2.2 Keypad 3
3PREPARATION 5
3.1 Inserting the Batteries 5
3.2 Connecting the Probe 6
3.3 Connecting the AC Adapter 7
4CALIBRATION 8
4.1 Temperature Calibration 9
4.2 DO Calibration in Air (with ATC) –% Saturation Mode 11
4.3 DO Calibration in mg/L Mode 13
5MEASUREMENT 14
5.1 Taking Measurement 14
6HOLD FUNCTION 15
7MEMORY FUNCTION 16
7.1 Data Input 16
7.2 Memory Recall 18
8SET FUNCTION 20
8.1 SET Function in % Saturation Measurement Mode 21
8.2 SET Function in mg/L or ppm Measurement Mode 31
9DISSOLVED OXYGEN PROBE 38
9.1 Dissolved Oxygen Principle 38
9.2 Probe Care 39
9.3 Membrane Housing Replacement 40
9.4 Electrolyte Solution 43
9.5 DO Probe Troubleshooting Table 44
10 TROUBLESHOOTING 46
11 ERROR MESSAGES 47
12 ADDITIONAL INFORMATION 48
12.1 Dissolved Oxygen 48
13 SPECIFICATIONS 51
14 ACCESSORIES 52
15 WARRANTY 54
16 RETURN OF ITEMS 54

Instruction Manual DO 100
1
1 INTRODUCTION
Thank you for selecting the DO 100 portable meter. The DO 100 portable meter is a
microprocessor-based instrument that is designed to be practical and user-friendly. It is
capable of measuring Dissolved Oxygen (DO) in mg/L or ppm units, % saturation and
temperature. 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 a submersible cable, spare
membrane cap; a bottle of replacement electrolyte solution, (4) AAA batteries, and instruction
manual. Please read this manual thoroughly before operating your meter.

Instruction Manual DO 100
2
2 DISPLAY AND KEYPAD FUNCTIONS
2.1 Display
The LCD has a primary and secondary display.
•The primary display shows the measured DO value either in mg/L, ppm or %,
depending on units of measurement selected.
•The secondary display shows the temperature in °C.
The display also shows error messages, keypad functions and program functions.
See Figure 1.
Figure 1: Full LCD Screen

Instruction Manual DO 100
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 mg/L measurement mode, the meter will be in mg/L
measurement mode when you switch the meter on.
HOLD 1. Freezes the measured reading. To activate, press HOLD while in
measurement mode. To release, press HOLD again.
2. In its SETUP menu, this key takes you through the main menu.
MODE 1. Selects the measurement parameter. Press MODE to toggle between %
Saturation and mg/L or ppm mode.
2. While in the CAL mode under mg/L or ppm measurement status, this key
will toggle between mg/L (ppm) calibration and temperature calibration
(refer to Section 4.1 on page 9 to 10.)
CAL/MEAS 1. Toggles between Calibration and Measurement mode.
If you were in Measurement mode, press CAL/MEAS to enter Calibration
mode. To confirm calibration, press ENTER key.
To abort calibration, press CAL/MEAS key again to go back to
measurement mode.
2. While in SETUP, pressing CAL/MEAS takes you out directly into the
measurement mode.
ENTER 1. Press to confirm your calibration values in Calibration mode.
2. While in SETUP, pressing ENTER key takes you through the various
menu AND through each sub-menu.
MI & MR
/ 
In measurement mode:
Press MI /to store values in mg/L or % Saturation values with its
corresponding temperature values in the memory. Up to 16 sets of values can
be stored.
Press MR/to retrieve data from memory in LIFO method.
In Calibration mode:
Scrolls up and down values with each key press, or helps make selection.
SET Takes you into the SETUP mode.

Instruction Manual DO 100
4
Figure 2: Keypad

Instruction Manual DO 100
5
3 PREPARATION
3.1 Inserting the Batteries
The DO 100 is packaged with 4 “AAA” alkaline batteries required for operation. To insert the
batteries into the meter, follow the procedure outlined below.
1. To open the battery compartment, press down the catch of the battery cover. See Figure
3a below.
2. Note the polarity and insert the batteries into the battery compartment correctly (Figure
3b).
3. Replace the battery cover into its original position, ensuring the catch is lock into its
position.
Your hand-held meter is now ready for operation.
Figure 3b: Battery position
Figure 3a: Back panel of meter
showing battery compartment
LR03 'AAA' (AM4)
MADE IN S'PORE

Instruction Manual DO 100
6
3.2 Connecting the Probe
The DO 100 uses a special notched 6-pin connector to attach the probe to the meter.
NOTE: Do not substitute other probes or electrodes. For replacement probe, see
the Section 14 “Accessories” on page 52.
NOTE: Keep connector dry and clean. Do not touch connector with soiled hands.
To connect the Dissolved Oxygen probe:
1. Line up the notch and 6 pins on the meter with the holes in the 6 pin connector. Push
down and screw the metal sleeve to lock the probe connector into place. See Figure 4.
2. 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.
Figure 4 - Probe Connector

Instruction Manual DO 100
7
3.3 Connecting the AC Adapter
The AC adapter is not included with your meter; see the Section 14 “Accessories” on page 52.
Ensure that the input mains voltage (110 or 220 V at 200 mA) matches your adapter
requirements.
1. Insert the AC jack as shown in Figure 5 below.
2. Switch off the meter before plugging the adapter into the power source. This safety
precaution protects the software in your meter.
3. Press the ON/OFF button to switch meter on.
Figure 5 - Using optional AC adapter

Instruction Manual DO 100
8
4 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. This is described in the
following section.
Before calibrating, press MODE key to select the correct measurement mode. There are 2
measurement modes for DO: mg/L or ppm, and % Saturation.
NOTE: All new calibrations will automatically over-ride existing calibration values.

Instruction Manual DO 100
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4.1 Temperature Calibration
DO in mg/L is dependent on temperature, so it is first necessary to
calibrate or verify the temperature reading. Temperature calibration is
accessible from the mg/L or ppm measurement mode. This is
illustrated in the flow diagram in Figure 7.
The temperature sensor is part of the DO probe and the “ATC”
annunciator will light up on the LCD screen once the probe is
connected correctly to the meter.
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. See Figure 6.
5. Press MI/or MR/key to set the correct temperature value.
NOTE: The meter allows a limit of ± 10 °C variation between the
original and the adjusted value.
6. Press ENTER key to confirm the adjusted temperature. The
temperature probe is now calibrated.
NOTE: To exit from Temperature Calibration mode without
confirming calibration, press CAL/MEAS key.
NOTE: 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.
Figure 6: Temperature
Calibration

Instruction Manual DO 100
10
Figure 7: Flow Diagram for Temperature and mg/L (ppm) Calibration

Instruction Manual DO 100
11
4.2 DO Calibration in Air (with ATC) –% Saturation Mode
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 Section 8.23 for barometric pressure
setting.
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 gently 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.
NOTE: To exit from DO Calibration mode without
confirming calibration, DO NOT press ENTER.
Press CAL/MEAS instead.
Figure 8: Calibration for 100%
Saturation

Instruction Manual DO 100
12
MEAS
READY
%
°C
ATC
SETUP
MEM OFF
SETUP
SETUP
SET
ENTER
ENTER
%
°C
ATC
MEAS
READY
ENTER
READY
%
SETUP
CAL
MEAS
To calibrate 0% Saturation:
1. Power on the unit and immerse the DO probe in
0% solution. Ensure that the tip of the probe is
completely immersed. Stir gently to create a
homogenous solution. Wait for the reading to
stabilise. It should be less than 10%.
2. Press SET key once to go to SETUP mode. The
SETUP indicator will appear above the primary
display.
3. Press ENTER key once. The “OFS- P2.0”
screen should appear.
4. Press ENTER key once to enter zero-point
calibration mode. Wait for the reading to
stabilise. If the READY indicator feature is
enabled, it will appear when the reading is
stable (see Ready indicator setup in section
8.1.7.).
5. Press ENTER key once. The meter
automatically calibrates to 0.0% saturation. The
next screen should show “bAr- P2.2”.
6. Press CAL/MEAS key once to exit out of
SETUP mode. The meter is now in
measurement mode and should display 0.0%
value.
NOTE: You can offset your % DO Calibration; see
page 24 for directions.
Figure 9: Calibration for 0.0%
Saturation

Instruction Manual DO 100
13
4.3 DO Calibration in mg/L Mode
As mentioned in the beginning of this section, the amount of
oxygen dissolved in a liquid will depend on its temperature,
pressure and salinity. It is therefore very important to set
these parameters correctly before attempting to do a
calibration.
Temperature is measured by the meter automatically.
Therefore it is important to do a Temperature Calibration (as
described in Section 4.1) before attempting DO calibration.
Pressure and salinity values are keyed in manually as
described in Sections 8.2.2 and 8.2.3.
1. From the measurement mode, press MODE key to
select mg/L.
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. Dip the probe into a solution where DO value is known.
4. Wait until the reading stabilises. Press CAL key.
5. Adjust to the required value by pressing MI/or MR/
key.
6. Press ENTER to confirm the calibration. See Figure
10.
NOTE: To exit from DO Calibration mode without
confirming calibration, press CAL/MEAS key.
Figure 10: DO Calibration

Instruction Manual DO 100
14
5 MEASUREMENT
During measurement, care must be taken not to allow the membrane of the DO probe touch
any surface. It is always advisable to insert the probe guard (refer to Figure 33 and 34 on
pages 40 and 41). The probe can either be fully or partially immersed in the solution.
The READY indicator appears on the display when the readings stabilise. It will turn off if the
readings start to fluctuate.
NOTE: It is important that the sample is stirred constantly to allow it to flow past the
membrane for better readings.
5.1 Taking Measurement
1. Rinse the probe with deionised or distilled water
before use to remove any impurities adhering to the
probe body. If it is dehydrated, soak it for 30
minutes in tap water.
2. Switch on the meter. The MEAS annunciator
appears on the top of the LCD. The ATC indicator
appears in the lower right hand corner to indicate
Automatic Temperature Compensation. See figure
on right.
3. Dip the probe into the sample.
NOTE: When dipping the probe into the sample, make
sure the tip of the probe is completely immersed. Stir the
sample gently to create a homogenous sample. Be sure
to tap probe very gently to remove air bubbles. Air
bubbles will cause errors in the reading.
4. Allow time for the reading to stabilise. Note the
reading on the display. When the reading is stable,
the READY annunciator appears.
5. To toggle between % Saturation and mg/L
measurement mode, press the MODE key. See
Figure 11.
Figure 11: Taking Measurement

Instruction Manual DO 100
15
6 HOLD FUNCTION
This feature lets you freeze the value of the DO
reading 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 12.
2. To release the held value, press HOLD again.
Continue to take measurements.
NOTE: This meter shuts off automatically after
20 minutes of last key press. If the meter
is shut off either automatically or
manually, the HOLD value will be lost.
For longer storage, use the memory
functions.
Figure 12: HOLD Function

Instruction Manual DO 100
16
7 MEMORY FUNCTION
The DO 100 can store up to 16 sets of data. Each data
stored can either be in % Saturation, mg/L or ppm together
with its respective temperature reading taken at that
moment.
Stored data can be easily recalled based on LIFO (Last-In-
First-Out) system.
7.1 Data Input
To clear all data from memory, refer to Sections 8.1.1 (page
23) or 8.2.1 (page 31) on the procedure.
1. Switch on the meter by pressing ON/OFF key.
2. Ensure the meter is in the appropriate measurement
mode, either mg/L or % Saturation. Press MODE key
for the desired measurement mode.
3. Place the probe into the sample to be measured.
4. After the reading is stabilised, indicated by the READY
annunciator, press MI/key. The MEM annunciator
will flash with a number indicating that the data has
been stored. See figure on right.
5. Place the probe into another sample and repeat from
step 2 above.
NOTE: The above illustration will be used in the next
Section, Memory Recall.
NOTE:
The number counter below MEM annunciator will increase
to 16 according to the following symbols:
Figure 13 Memory Input