EUTECH INSTRUMENTS DO 6PLUS DISSOLVED OXYGEN TEMP User manual

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Instruction Manual
DO 6+ Dissolved Oxygen/Temp
68X243634
Rev 0 Mar 09
Part of Thermo Fisher Scientific

Instruction Manual DO 6+

Instruction Manual DO 6+
Preface
This manual serves to explain the use of the DO 6+ hand held meter.
This manual functions in two ways: first as a step by step guide to help you
operate the meter; second, as a handy reference guide.
This manual is written to cover as many anticipated applications of the DO 6+
meter as possible. If there are doubts in the use of this meter, please do not
hesitate to contact the nearest Eutech Instruments Authorized Distributor.
Eutech Instruments will not 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.
Copyright © 2009
Eutech Instruments Pte Ltd
All rights reserved.

Instruction Manual DO 6+

Instruction Manual DO 6+
Table of Contents
1. INTRODUCTION ...............................................................1
2. GETTING STARTED.........................................................2
2.1 Description of Keypad Functions ...................................................................2
2.2 Description of LCD Annunciators...................................................................3
2.3 Inserting & removing the rubber armour / stand.............................................4
2.4 Inserting New Batteries.................................................................................4
2.5 Battery Replacement .....................................................................................5
2.6 Connecting the Electrode...............................................................................5
2.7 Electrode Information.....................................................................................6
2.8 Switching the Meter On .................................................................................7
2.9 Changing Mode .............................................................................................7
3. CALIBRATION..................................................................8
3.1 General Information .......................................................................................8
3.2 Temperature Calibration ................................................................................10
3.3 % Saturation Calibration ................................................................................11
3.3.1 100% Calibration ...............................................................................11
3.3.2 0% Calibration ...................................................................................12
3.4 mg/L or ppm Calibration ................................................................................13
4. MEASUREMENT ..............................................................14
4.1 Temperature Compensation ..........................................................................14
4.2 Taking Measurements ...................................................................................15
4.3 Pressure & Salinity Compensated Measurements .........................................16
4.4 Holding a Reading .........................................................................................16
5. SETUP...............................................................................17
5.1 Configuration Menu (COF.1)..........................................................................21
5.2 Automatic Temperature Compensation (A.ATC)............................................21
5.3 Selection of mg/L or ppm (b.DO) ...................................................................22
5.4 Calibration Data (CAL.2)................................................................................22
5.5 Electrode Data (ELE.3)..................................................................................23
5.6 Automatic Shut Off (AtO.4) ............................................................................24
5.7 Reset to Factory Default (rSt.5) .....................................................................25
5.8 % Saturation Offset Adjustment (OFS.6) .......................................................26
5.9 Pressure & Salinity Adjustment......................................................................27
6. PROBE MAINTENANCE ..................................................29
6.1 Cap and Electrolyte Replacement..................................................................30
6.2 Electrolyte Solution........................................................................................31
7. TROUBLESHOOTING ......................................................31
8. ERROR MESSAGES ........................................................32

Instruction Manual DO 6+
9. FACTORY DEFAULT SETTINGS ....................................33
10. SPECIFICATIONS ............................................................34
11. REPLACEMENTS AND ACCESSORIES.........................36
12. DISSOLVED OXYGEN THEORY .....................................37
Measurement Units.....................................................................................................38
What Is Being Measured?...........................................................................................38
Air Calibration .............................................................................................................39
Applications ................................................................................................................39
13. WARRANTY......................................................................40
14. RETURN OF ITEMS..........................................................40

Instruction Manual DO 6+
- 1 -
1. INTRODUCTION
Thank you for purchasing the DO 6+. This microprocessor-based handheld
meter is economical and easy to use. It has a large custom LCD (Liquid Crystal
Display) for clear and easy reading.
The DO 6+ offers measurement of dissolved oxygen (DO) as percentage
saturation or concentration. Temperature measurement is also available in
degrees Celsius. The meter ensures accurate measurement of the dissolved
oxygen values through its temperature, barometric pressure and salinity
compensation features.
Meter kits include a dissolved oxygen probe, refill solution, a rubber armour /
stand, 4 alkaline “AAA” batteries, instruction manual, and warranty card. For
additional information, see Section 11 — REPLACEMENTS AND
ACCESSORIES.
Please read this manual thoroughly before operating your meter.

Instruction Manual DO 6+
- 2 -
2. GETTING STARTED
2.1 Description of Keypad Functions
Your meter has 6 keys on its splash-proof keypad.
Some buttons have multiple functions depending
on the mode of operation.
ON/OFF Powers meter on and off. Meter starts
up in the measurement mode that you
last switched off from.
CAL Enters into calibration mode. Pressing
while in calibration mode will abort
calibration without confirming value.
MODE Selects desired measurement mode.
When pressed simultaneously with
ON/OFF, it will take you into the SETUP mode.
For more information see Section 5 — SETUP.
HOLD Freezes measured reading. Press again to resume live reading.
ENTER Confirms calibration value in calibration mode and confirm selections
in SETUP mode.
 Increment/decrement values during calibration mode or scroll through
SETUP menus. Set offset adjustments and configuration settings.

Instruction Manual DO 6+
- 3 -
2.2 Description of LCD Annunciators
Your meter has a large custom LCD that consists of 4-digit segments plus
annunciators for percentage saturation (%), concentration (mg/L or ppm) and
Temperature in degrees Celsius (T).
Other annunciators include “A” (when the ATC function is activated), “CAL”
(when meter is in calibration mode) and low battery condition.
Active LCD display for DO 6+
milligram per litre
(Concentration Mode)
mg/l
ppm
%
TA
14-segment Liquid Crystal Display
Low Battery annunciato
r
Calibration Mode
Annunciator
CAL
Temperature Mode
A T C annunciator
parts per million
Percentage
(Percentage Saturation
Mode)

Instruction Manual DO 6+
- 4 -
2.3 Inserting & removing the rubber armour / stand
1. To remove meter from rubber armour, push out from the bottom edges of
meter until it is completely out of boot. Ensure that your electrode cables
are not connected. See Figure 1.
2. To insert meter into armour, slide in from the top of meter before pushing
the bottom edges of meter down to set it into position. Lift up the stand at
the back of meter for bench top applications if necessary. See Figure 2.
Ing New Batteries
2.4 Inserting New Batteries
The battery compartment is found at the back of instrument. To open the battery
compartment, push in the direction of arrow and lift up the cover. Note the
polarity of battery before inserting into position. After replacement, place cover
back and press down until it locks.
Figure 1 Figure 2
2

Instruction Manual DO 6+
- 5 -
2.5 Battery Replacement
A low battery annunciator in the LCD alerts you when battery power is running
low. Caution: Power off the meter before replacing battery.
%
Low Battery Condition
2.6 Connecting the Electrode
1) To connect the electrode, align the connector slots with the posts of
meter’s socket and rotate connector clockwise until it locks.
2) To remove, rotate the connector in anti-clockwise direction until it
unlocks, and slide the connector off the socket.
3) Insert the mini phono jack of temperature sensor into the socket on the
meter as shown below.
BNC connector
2.5 mm mini phono
for temperature

Instruction Manual DO 6+
- 6 -
2.7 Electrode Information
The DO 6+ includes a galvanic DO electrode
(93X233912) which doesn’t require warm-up. It
generates a millivolt signal proportional to the
amount of oxygen in the solution.
The electrode has a dual cable; a BNC connector
for DO measurement and a phono jack plug for
temperature. The sensor utilizes a cathode,
anode, and electrolyte that are separated from
the sample by an oxygen permeable membrane.
The membrane is pre-assembled for you and
fixed to a detachable cap. The pre-assembled
cap design allows simple replacement and fast
conditioning.
The probe is light weight and includes a built-in
temperature sensor. The epoxy body of the probe
is 12mm diameter while the detachable Noryl cap
is 16mm diameter. The compact sensing area
reduces air entrapment resulting in quick,
accurate, and stable readings.
The pre-assembled cap must be completely
submersed to obtain an accurate reading in
solutions. Provide simple stirring for best
results—ideally achieve a minimum water flow
rate of 2 inch/second on the membrane. The
probe is not recommended beyond 0 to 50 °C.
Shaking will aid to remove bubbles if needed
before taking a reading. When calibrating in air,
shake to remove water from the membrane.
The membrane is thin and can not be repaired if
damaged. Use care to protect from scratches,
abrasion, or contact with solids. For best results
keep membrane clean by rinsing after daily use.
See Section 6 – PROBE MAINTENANCE.
Galvanic DO probe
(93X233912)
Detachable
Pre-membraned Cap
(Probe Sensing Area)
16 mm
12 mm

Instruction Manual DO 6+
- 7 -
2.8 Switching the Meter On
Press ON/OFF to power up your meter. Your meter will
cycle through various setup parameters when switched on.
1) All LCD segments will briefly illuminate.
2) The model [DO 6+] will display next along with mg/l,
ppm, and % annunciators.
3) Next, the meter revision number [r #.##] is shown
briefly before beginning measurement.
4) The meter begins with the measurement mode that
was in use when it was previously powered off⎯%,
mg/l, ppm, or T.
2.9 Changing Mode
Press MODE to switch between percentage saturation (%), concentration
(mg/L)(ppm), and temperature (T) measurement.
CAL 13 CAL 24
mg/l
NTU
ppm
%pH
TAvg
mg/l
ppm
%
ON
OFF
A
%
mg/l
A
TA
A
%
MODE
MODE
MODE
Percentage Saturation
Concentration Mode
Temperature Mode
Automatic Temperature
Compensation

Instruction Manual DO 6+
- 8 -
3. CALIBRATION
3.1 General Information
The DO 6+ has three measurement modes; DO as % saturation, DO as mg/L
(or ppm) concentration, and temperature.
Dissolved oxygen levels vary with temperature, barometric pressure, and
salinity, so calibration must be performed with consideration of these factors. It
is necessary to set the proper temperature, barometric pressure and
salinity values prior to performing any DO calibration or measurement.
See Section 3.2 — Temperature Calibration
See Section 5.2 — Automatic Temperature Compensation.
See Section 5.9 — Pressure & Salinity Adjustment.
The DO 6+ will accept two % saturation calibration points; 100% using
saturated air or air-saturated water, and 0% using zero oxygen solution. When
100% calibration is performed, the corresponding concentration is adjusted
simultaneously. Therefore, it is not necessary to calibrate the concentration
mode. If calibrating for 0% oxygen, note that the meter will take several minutes
to reach 0% saturation value and constant stirring is not required.
The following table lists calibration values in % saturation calibration mode with
two different barometric pressures. Note that the saturation value (92.1%) has
decreased due to the lower barometric pressure entered.
% Saturation (per
factory default value)
Calibration Value
(760mmHg)
Calibration Value
(700mmHg)
less than 10% 0% 0%
10.1% to 49.9% Err.1 (error 1) Err.1 (error 1)
50% to 200% 100% 92.1%
If calibration is attempted from 10.1% to 49.9%, the “Err.1” message is shown—
calibration is rejected and the display will return to measurement mode.

Instruction Manual DO 6+
- 9 -
The DO 6+ will accept one calibration point in concentration mode. The
minimum value is 2 mg/L (ppm), and the calibration window is +/- 40% of the
factory default value.
Temperature and % saturation calibration should take place before attempting
to perform mg/L (ppm) concentration calibration.
Calibration of the concentration mode will only replace the previous
concentration calibration and does not affect the % saturation calibration.
To offset your % saturation reading to match another instrument, see Section
5.8 — % Saturation Offset Adjustment.
New calibration values will automatically override the existing data. Perform
daily calibration for best results. To completely recalibrate the meter and when
installing a replacement electrode, it is best to clear all calibration data. See
Section 5.7Reset to Factory Default.

Instruction Manual DO 6+
- 10 -
3.2 Temperature Calibration
For best DO accuracy, ensure that the
temperature is accurate. The temperature
sensor of the DO 6+ probe has been
factory calibrated, however if it changes
over time or if the probe is replaced,
calibration may be necessary. To protect
from erroneous calibrations, the allowable
tolerance is limited to ±5°C adjustment of
the factory default value.
Most users utilize automatic temperature
compensation using the sensor that is built
into the probe. However, manual
temperature compensation can be used to
input a fixed, known temperature.
1) Press MODE to select temperature
mode. The display should show “T”
for temperature and “A” for automatic
temperature compensation.
2) Dip the probe into a solution with a
known, accurate temperature (i.e. a
temperature bath). Allow enough time
for the temperature reading to
stabilize.
3) Press CAL. The CAL indicator will
blink above the display. The
temperature value shown is the value based on the factory default.
4) Press ▲▼to adjust the reading to match the correct temperature value
(i.e. of the temperature bath).
5) Press HOLD/ENTER to confirm the calibration and return to measurement
mode.
Press CAL as needed to exit calibration without confirmation at any time.
CAL
CAL
T
T
A
A
TA
TA
CAL
HOLD
ENTER
Factory default
Temperature
Measurement
“CO” will display for
1.5 seconds

Instruction Manual DO 6+
- 11 -
3.3 % Saturation Calibration
The DO6+ can be easily calibrated in air. For best DO accuracy, ensure that the
barometric pressure value is accurate.
The barometric pressure factory default is
760 mm Hg, which results in a theoretical
calibration value of 100% saturation in air.
If the barometric pressure setting has been
changed from 760 mm Hg, the meter will
automatically adjust to a new % saturation
calibration value instead of 100%. This new
value is correct for the adjusted barometric
pressure.
3.3.1 100% Calibration
1) Rinse the probe well with DI water or
rinse solution.
2) Press MODE to select % saturation.
3) Hold the probe in the air with the tip
facing downwards. Wait for the
reading to stabilize.
4) Press CAL. The CAL indicator and
intended percentage calibration point
(100%) display briefly, before CAL
flashes. The % value based on the
factory default calibration is shown.
5) Press HOLD/ENTER to confirm the
calibration. The meter displays “CO”,
automatically calibrates to 100.0% air
saturation, then returns to
measurement mode.
%
CAL
A
%
HOLD
ENTER
CAL
CAL
%
Calibration point will be
displayed for 1.5 seconds
%
A
value with respect to the
factory default calibration
will be displayed
“CO” will displayed for
1.5 seconds
A

Instruction Manual DO 6+
- 12 -
3.3.2 0% Calibration
1) Rinse the probe well with DI water or
rinse solution.
2) Press MODE to select % saturation.
3) Dip the probe into zero oxygen
solution. Wait for the reading to
stabilize.
4) Press CAL. The CAL indicator and
intended percentage calibration point
(0%) display briefly, before CAL
flashes. The % value based on the
factory default calibration is shown.
5) Press HOLD/ENTER to confirm the
calibration. The meter displays “CO”,
automatically calibrates to 0.0%
saturation, then returns to
measurement mode.
A
value with respect to the
factory default calibration
will be displayed
%
CAL
A
%
HOLD
ENTER
CAL
CAL
%
Calibration point will be
displayed for 1.5 seconds
%
“CO” will displayed for
1.5 seconds
A

Instruction Manual DO 6+
- 13 -
3.4 mg/L or ppm Calibration
Performing a 100% saturation calibration will
simultaneously calibrate the corresponding
mg/L (ppm) concentration value. Therefore,
additional mg/L (ppm) calibration isn’t
required in most circumstances.
If desired, you can perform a calibration
adjustment in mg/L (ppm) without affecting
your % saturation calibration value.
1) Perform 100% saturation calibration.
See Section 3.3.1 — 100% Calibration.
2) Rinse the probe well with DI water or
rinse solution.
3) Dip the probe into a sample of known
oxygen concentration (i.e. determined
by titration or another instrument). Wait
for the reading to stabilize.
4) Press MODE to select the mg/L (ppm).
5) Press CAL. The CAL indicator and
current concentration display briefly,
before CAL flashes. The concentration
value based on the factory default
calibration is shown.
6) Press ▲▼to adjust the reading to
match the known oxygen concentration
value.
7) Press HOLD/ENTER to confirm the
calibration. The meter displays “CO”, automatically calibrates to the
entered value, then returns to measurement mode.
NOTE: The minimum calibration value is 2 mg/L. To prevent erroneous
calibrations, the calibration is limited to ±40% adjustment of the factory default
value.
mg/l
mg/l
mg/l
CAL
CAL
HOLD
ENTER
CAL
mg/l
“CO” will display
for 1.5 seconds
A
A
A
value with respect to the
factory default calibration
will be displayed

Instruction Manual DO 6+
- 14 -
%
A
A
utomatic Temperature
Compensation activated
4. MEASUREMENT
The DO 6+ offers automatic or manual temperature compensation.
See Section 5.2 — Automatic Temperature Compensation.
4.1 Temperature Compensation
Insert the phono plug of the probe for Automatic Temperature Compensation
(ATC). The “A” annunciator will display normally when active, or blink if the
phono plug is disconnected.
Deactivate “A.ATC” for manual temperature
compensation. The “A” annunciator is not
displayed when the meter is in manual
temperature compensation mode.
For manual temperature compensation, manually
enter the desired process temperature into the
meter from 0 and 50 °C. Default is 25 °C.
1) Press MODE to select temperature.
2) Press CAL. The “CAL” indicator will start
blinking and the display will show the last
manually set temperature value.
3) Check the temperature of your sample using
an accurate reference thermometer. Wait for
the value to stabilize. Press ▲▼to manually
set the temperature value.
4) Press HOLD/ENTER to confirm the
calibration. The meter displays “CO”,
automatically sets the entered value, then
returns to measurement mode.
CAL
CAL T
T
T
T
CAL
HOLD
ENTER
Last set manual
temperature setting
“CO” will display for 1.5
seconds