Contech CDO-01 User manual

INSTRUCTION MANUAL
DISSOLVED OXYGEN-METER
MODEL CDO-01
EL-221, MIDC Electronic Zone, Mhape, Navi Mumbai-400710 Tel: 022-

61393000
CHAPTER 1
INTRODUCTION
Contech CDO-01 measures Dissolved Oxygen and temperature of liquids It can be used
in a variety of fields such as industrial, agriculture, environmental studies and scientific
research laboratory
ABOUT CDO-01 MODEL.
Dissolved Oxygen meter, Model CDO-01, is a microprocessor based instrument, which
measures Dissolved oxygen and salinity and temperature of a liquid under test Meter
supports ATC (Automatic temperature compensation) feature which corrects the electrode
output changes due to temperature variation of the sample being tested There is also an
option to enter the temperature of measuring solution manually Also there is an option to
enter the Atmospheric Pressure for correcting changes due to it The following are the
salient features of CDO-01 meter
Advanced Microprocessor based design
DO and Conductivity
DO in Saturation % and mg/L
DO correction for Temperature, Atmospheric pressure and Salinity
Polarographic Electrode
Automatic and Manual temperature Compensation
Single or Multi point calibration of Salinity
Cell Constant adjustable from 0 1 to 10 0
Temperature Coefficient adjustable from 0 to 10%/ oC
Normalisation temperature adjustable from 15 to 30 oC
Bi directional RS232 interface Baud rate selectable from 1200,2400,4800 and
9600
Single and continuous print out of DO and Conductivity
Multiple Printout types Combinations selectable from Sr No , DO/Conductivity,
Date, time and temperature
Real Time Clock
Temperature setting (Manual temperature compensation)
Calibration report as per GLP requirements
LCD display with Backlight
Memory storage of 100 measurements
Data logging facility up to 500 results Data logging interval selectable from 5S,
10S, 20S, 30S, 1M, 2M and 5M

Temperature calibration
Atmospheric Pressure Entry
CHAPTER 2
DO METER DISPLAY
DO METER KEYBOARD

CHAPTER 3
BASIC OPERATION AND SETUP PARAMETERS
3.1 POWER AND INSTALLATION REQUIREMENTS
The meter requires good stable power Meter is supplied with a 9V/1A switching adapter
Connect the adaptor to the instrument to the power jack located at the rear side of the
meter Connect the adapter to an AC power outlet Meter is supplied with a probe
Connect the electrode to the BNC connector provided at the rear side Connect the
temperature probe to the temperature input connector
3.2 STARTING THE METER
Switch on the meter by pressing the key Instrument goes through self-tests and
subsequently display the measured Saturated DO say 99 7%

3.3 CHANGING MODES.
Use to change between DO and CONDUCTIVITY modes
Press key to change between Saturated DO %, Do in ppm and mg/L
3.4 SETUP PARAMETERS
3.4.1 SETTING DATE AND TIME.
Meter has an inbuilt Real Time clock Hence there is no need to change or update date
and time However it is possible to change date and time

Press key The Meter displays
and subsequently displays
Press or key till it displays
Press key Meter displays current date say 07 Follow the instructions below for
changing date, month and year
Meter Displays the current time, say 12 23 45

Press key to change hour Follow the instructions below for changing
Hour and Minute
3.4.2 TO SET BAUD RATE
Press key The Meter displays
and subsequently displays

Press key Meter displays the set baud rate say 9600
Press or key to change between 1200, 2400, 4800 and 9600 and press
key to save
Press key to quit without saving
3.4.3 TO SET TEMPERATURE For Manual Temperature
Compensation)
Press key The Meter displays
and subsequently displays
Press or key till it displays
Press key
Meter shows the set or default temperature (25oC)
Press or key to change temperature and press key to save
Press key to quit without saving
3.4.4 TO SET READING SERIAL NUMBER

Press key The Meter displays
and subsequently displays
Press or key till it displays
Press key Meter shows the current serial number
Press or key to change the serial number and press key to
save
Press key to quit without saving
Press key to make the reading 0000
3.4.5 TO SET PRINT OPTION
There are 2 options : and
- Press key to print current DO/Cond through RS232 port
- Continuous data transfer to computer/printer through RS232 port
Press key The Meter displays
and subsequently displays
Press or key till it displays
Press key Meter displays the current mode, say One

Use or keys to change between
and and Press key to save
Press key to discard changes and quit
3.4.6 TO SET PRINT FORMAT.
There are 6 print formats available in the meter
- ONLY DO/Cond
- SERIAL NO, DO/Cond
- SERIAL NO, DATE,DO/ Cond
- SERIAL NO, TIME, DO/Cond
- SERIAL NO, DATE, TIME, DO/Cond
- SERIAL NO, DO/Cond, TEMPERATURE
To change the format,
Press key The Meter displays
and subsequently displays
Press or key till it displays
Press key Meter displays the current mode
Use or keys to change between PRF-1 to PRF-6 and press
key to save

Press key to discard changes and quit
3.4.7 . TO SET PRINT TYPE.
Meter can be set to print the results in Horizontal and vertical form
A Typical printout in the horizontal form appears as below
1 12 30 34 7 75 mg/L
2 12 30 45 7 82 mg/L
While a printout in vertical mode is as shown below
Sr No : 1
Time : 12 30 34
Value : 7 75 mg/L
To set the mode,
Press key The Meter displays
and subsequently displays
Press or key till it displays
Press key Meter displays the current mode,
say TYPE1
Press or key to change between (horizontal) and
(Vertical) and press key to save
Press key to discard changes and quit

3.4.8. TO SET MACHINE ID.
Machine identification number can be assigned to the meter using this option
Press key The Meter displays
and subsequently displays
Press or key till it displays
Press key Follow the instructions given below for setting id
3.4.9. TO SET TEMPERATURE COEFFICIENT.
Press key The Meter displays

and subsequently displays
Press or key till it displays
Press key Meter will display the current value of coefficient say 2 00
Use or key to change and Press to save
Press key to discard changes and quit
3.4.10. TO SET NORMALISATION TEMPERATURE.
Using Automatic temperature compensation, Meter compensates for temperature
variations of a solution from the normalization temperature set Default normalization
temperature is 25oC However it can be changed from 15 to 30oC, if required
Press key The Meter displays
and subsequently displays
Press or key till it displays
Press key Meter will display the current value of temperature say 25
Use or key to change and Press to save
Press key to discard changes and quit

3.4.11. TO SET CELL CONSTANT.
Press key The Meter displays
and subsequently displays
Press or key till it displays
Press key Meter will display the current value of cell constant say 1 00
Use or key to change and Press to save
Press key to discard changes and quit
3.4.12. TO SET ATMOSPHERIC PRESSURE.
Press key The Meter displays
and subsequently displays
Press or key till it displays
Press key Meter will display the current value of atmospheric pressure say 760
Use or key to change and Press to save

Press key to discard changes and quit
CHAPTER 4
DISSOLVED OXYGEN MEASUREMENTS
4.1.. DO ELECTRODE.

CDO-01 Electrode is illustrated above
It is a Polarographic type electrode It needs about 5 minutes of electrode polarization
whenever it is switched on It has a removable electrode cap for convenience
It has an outer calibration cover which protects the membrane cap Unscrew the bottom
lid and check if the sponge is still soaked If not add few drops of distilled water Ensure
that the water is just enough to soak the sponge and it should not remain in the calibration
cover Put the bottom lid back into the calibration cover and fix it tightly
Remove the Calibration cap by unscrewing the cover cap
Unscrew Membrane Cap from the electrode Check if contains full electrode solution If
not, add few drops of electrode solution just enough to make it full Plug the membrane
cap back to the electrode Whenever electrode solution is added or changed, connect the
electrode to the meter, put the meter on and polarize it for at least 15 minutes

Electrode also has sensors for measuring salinity Ensure that the salinity sensor is
completely immersed in the liquid under test for effecting proper salinity correction
4.2. DO ELECTRODE CALIBRATION.
Put the meter on Polarize the electrode for atleast 5 minutes by connecting it to the
meter Put the meter in % Saturation Mode
Keep the Electrode vertically to polarize for at least 5 minutes and wait for the display to
become stable
Alternately remove the calibration cover and keep the electrode vertically for at least 5
mintes for polarization
Wait for the display to become stable
Press key Wait for meter to display
Electrode calibration is now complete
4.2.1 ZERO OXYGEN CALIBRATION.
Zero Oxygen calibration is required when the electrode/electrode cap is replaced or the
meter is unused for long time Zero oxygen calibration is done at factory and generally

meter need not be calibrated for zero oxygen levels unless the conditions mentioned
above occur
For zero oxygen calibration, mix 5g of anhydrous sodium sulphite (Na2SO3) into 100 ml
of pure distilled water Mix it thoroughly to make a homogenous solution
Polarize the electrode for 15 minutes by connecting it to the meter
Press key The Meter displays
Immediately press and keys together
Meter displays
And subsequently displays the current signal value
Immerse the DO electrode into the above zero oxygen calibration solution and keep it
polarized for about 10 minutes
Wait for the display to become stable and Press key

Meter Displays and subsequently displays the current signal
value
Remove the electrode from the solution and press make it dry and hold it vertically for
about 10 minutes
Wait for the display to become stable and Press key
Meter is now calibrated for zero and saturated oxygen It displays
4.3. SALINITY ELECTRODE CALIBRATION.
CDO-01 can be calibrated for salinity in both manual and auto modes Automatic
calibration can be done in Conductivity mode only But Manual calibration also can be
performed Meter also allows Single and Multi point calibration
In case of Single point calibration, when a calibration is performed in one Range,
Calibration of all the 5 ranges will be changed However in Multi point calibration, new
calibration value will be the change in the range of the calibration solution only
Always use fresh solution for calibration For optimum results, choose calibration
standards close to the values being measured Use Single point calibration, if
measurement is done in one single range For measurements in different ranges, use multi
point calibration While Calibration solution of 1413 uS/cm takes care of the 0 –2000 us
range, 84us/cm solution can be used for 0 – 200 us/cm or 12 88 mS/cm for 0 – 20 ms
range As a thumb rule use a calibration solution which is atleast 60 –70% of the range

Calibrate the meter frequently atleast once a week for better results There may be
situations where the meter must be calibrated before use
4.3.1 SETTING AUTO / MANUAL MODES.
Press key The Meter displays
and subsequently displays
Press or key till it displays
Press key Meter will display the current calibration type
Use or keys to change between (Manual) and
(Auto)
Press key to select the mode
4.3.2 SETTING SINGLE / MULTI MODES.
Press key The Meter displays
and subsequently displays
Press or key till it displays
Press key Meter will display the current calibration mode