Dissolved Oxygen - Interautomatika

Dissolved Oxygen - Interautomatika
Dissolved Oxygen
Dissolved Oxygen
The measure of the amount
of gaseous oxygen dissolved
in a solution.
Handheld:
1. CyberScan DO 600
2. CyberScan DO 300
3. CyberScan DO 110
4. DO 6+
Bench:
1. DO 2700
2. DO 700
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page | 51
DO
About Dissolved Oxygen
Measurement
About Dissolved Oxygen Measurement
What is Dissolved Oxygen?
Dissolved Oxygen
Dissolved Oxygen (DO) is a measure of the amount of dissolved
gaseous oxygen in a solution. Some gases, such as ammonia, carbon
dioxide and hydrogen chloride, react chemically with water to form
new compounds. However, gases such as nitrogen and oxygen merely
dissolve in water without chemically reacting with it, and exist as
microscopic bubbles between water molecules.
There are two main ways in which dissolved oxygen occurs naturally
in water: From the surrounding atmosphere, where oxygen in the
surrounding air dissolves readily when mixed into water, up to
saturation, during water movements; Via photosynthesis when oxygen is
produced by aquatic plants and algae as a by-product of photosynthesis.
The amount of oxygen dissolved in water is usually measured in percent
saturation, or expressed as a concentration in milligrams per litre water.
Accurate measurement of dissolved oxygen is essential in processes
where oxygen content affects reaction rates, process efficiency or
environmental conditions, such as biological wastewater treatment,
wine production, bio-reactions, environmental water testing.
Basic Principle in DO Measurement
In theory, the amount of DO in a solution is dependent on three factors,
namely temperature, salinity and atmospheric pressure.
1.Water Temperature
Solubility of oxygen reduces as temperature increases. Hence, the
colder the water, the more dissolved oxygen it contains. Since
temperature affects both the solubility and diffusion rate of oxygen,
temperature compensation is necessary for any standardized
DO measurements.
All Eutech DO meters come with automatic temperature
compensation for accurate readings even in varying
temperature conditions.
2.Salinity
The amount of dissolved oxygen increases as salinity level decreases.
In other words, freshwater holds more oxygen than saltwater. Since
the presence of dissolved salts limits the amount of oxygen that can
dissolve in water, the relationship between the partial pressure and
concentration of oxygen varies with the salinity of the sample.
Eutech meters feature manual salinity correction to compensate
for variations in ionic concentration. Simply enter the salinity
of the sample in parts per thousand (ppt) to ensure the correct
DO measurements.
3.Atmospheric Pressure
There is a direct proportional relationship between the solubility
of dissolved oxygen and the surrounding atmospheric pressure. As
pressure decreases with increase in altitude, the amount of dissolved
oxygen found in water reduces.
To ensure that your dissolved oxygen is not affected by atmospheric
pressure, Eutech meters come with manual barometric pressure
compensation, with an Atmospheric Pressure Correction Chart
included in the manuals for convenient referencing.
page | 52
Eutech DO instruments automatically compensate for
temperature, salinity and barometric pressure. The salinity
value and barometric pressure are either measured by the
instrument or entered by the user.
DO Electrodes
The measurement of DO requires a special DO electrode that is made
up of an anode, a cathode, electrolyte solution and a gas permeable
membrane. The material of the membrane is specially selected to permit
oxygen to pass through. Oxygen is consumed by the cathode which will
create a partial pressure across the membrane. Oxygen then diffuses
into the electrolyte solution. In short, a DO meter actually measures the
pressure caused by movements of oxygen molecules in water or any
other medium. Currently, galvanic and polarographic electrodes are the
predominant methods for measuring dissolved oxygen.
The Galvanic Cell consists of two metals, the positive anode and the
negative cathode, connected by a salt bridge between the individual
half-cells. As the metal electrodes leave electrons behind as they
dissolve in the electrolyte. The different properties of the two metals
causes them to dissolve at different rates, hence a pressure is created
when the number of electrons in either side of the cell differs. The
pressure is translated into an electric current proportion to the oxygen
concentration in the electrolyte if an electrical circuit is created between
the two electrodes. The galvanic electrode does not need polarising
time and is able to assume operation immediately.
During this process, ions of the more active anode are transferred
through the electrolyte to the less active cathode, and deposited there
as a plating. In this way the anode is corroded. When the anode material
eventually corrodes away, the potential drops and the current halts.
G alvanic elec trodes are available with most Eutech
Instruments DO meters such as the DO 6+, CyberScan
DO 110 and DO 300.
The Polarographic Cell consists of two electrodes placed in the
electrolyte: One with fixed potential called the reference electrode,
and the other with a variable potential called the polarizable electrode.
As voltage is applied to the polarizable electrode, a redox reaction
occurs, where electrons break away from the electrode to bond
with oxygen in the electrolyte. The rate at which the electrons break
DO
About Dissolved Oxygen
Measurement
away from the polarizable electrode is linearly proportionate to the
amount of oxygen available in the electrolyte, hence this movement
of electrons is representative of the amount of dissolved oxygen left
in the electrolyte.
The advantage of a polarographic cell is that the cathode remains intact.
The current flow of the polarographic cell is also linearly proportional
to the amount of oxygen present in the electrolyte, enabling the cell to
provide highly accurate measurements at low oxygen levels.
Polarographic self-stirring DO/BOD probes are available for use
with the Eutech DO 700 and DO 2700 bench meters.
BOD & COD
BODt (mg/L) =
Dissolved Oxygen
The BOD test measures the molecular oxygen utilized in the
biodegradation of organic material and the oxidation of inorganic
material. By measuring the amount of oxygen dissolved in samples at
the beginning and end of a specified incubation period, the relative
oxygen requirements of wastewaters, effluents, and polluted waters
can be determined.
D1 - D2
P
BODt= Oxygen uptake during incubation period t
D 1
= DO of diluted sample immediately after preparation (mg/L)
D 2
= DO of diluted sample after incubation period t (mg/L)
P
= Decimal volumetric fraction of sample used
BOD is similar to the Chemical Oxygen Demand (COD), which
also measures relative oxygen-depletion. However, the possible
presence of non-biologically oxidisable may render the COD test to
be less accurate.
The COD Test is often used to measure the amount of organic
compounds in surface water by measuring the amount of oxygen
required to oxidize and break down an organic compound into carbon
dioxide, ammonia and water. The basis of the COD test is that anything
can be oxidized into carbon dioxide using a strong oxidizing agent in
acidic environments. A blank sample, created by adding all reagents to
distilled water is usually used as a control in COD measurements.
Both the BOD and COD tests are means to measure the relative
oxygen-depletion effect of a waste contaminant, and are widely used
to monitor pollution levels. The BOD test measures the oxygen demand
of biodegradable pollutants whereas the COD test measures the
oxygen demand of biogradable pollutants plus the oxygen demand of
non-biodegradable oxidizable pollutants.
However, because COD measures everything that can be chemically
oxidised and not just the level of biologically active organic matter, the
possibility of non-biological oxidizable may render the COD Test as a
less accurate method compared to the BOD method.
>> Water Treatment
<< Shrimp Farming
page | 53
DO
CyberScan Waterproof
Handheld
CyberScan DO 600
Dissolved Oxygen/ºC/ºF
Fast, intuitive and powerful – the CyberScan DO 600 offers one of the widest measurement ranges and
biggest memory spaces in the DO handheld market today. Data-transfer is easy with incorporated IrDA
wireless communications technology: No wires, no cables. Send data with the press of a button!
Dissolved Oxygen
Wireless data transfer
Waterproof external
power input
Large backlit screen
with multi-data
display and intelligent
prompt messages
Complimentary
Cybercomm 600 software
– download data from
meter to PC as text or
Excel® spreadsheet
Intuitive soft-key
operation
Rugged and
IP67 waterproof
Sturdy rubber boot
doubles up as meter stand
Applications
Aquacultural: Use to monitor oxygen levels in
catfish and shrimp farming; game stocking
ponds; ornamental fish tanks and ponds;
and in other fish farming applications.
Industrial: Ideal for checks on the quality
of plant water intake and discharge,
wastewater and water treatment, recirculating
systems and industrial process systems.
Environmental: Use to test water quality,
monitor health of aquatic ecosystems,
survey surface and ground water drinking supplies, and meet EPA regulations.
Educational: Ideal for quick, accurate DO
readings in laboratories and schools.
page | 54
Wide Measurement Range
• Measures oxygen concentration up to 90.00 mg/L and saturation up to 600.0 %
• Accurate readings even in varying conditions with Temperature, Salinity and Barometric
Pressure Compensation
User-Friendly
• Cal-due alarm for periodic calibration updates
• IP67 waterproof design for applications in harsh environments
• High/low set-points function for quality control checks – meter warns when readings fall outside
set limit
• Built-in barometer for auto-pressure correction
Advanced Data-Management
• Auto-logging function that automatically records up to 500 data sets in GLP-compliant format
• RS232C through LED*, IrDA wireless communications technology
* RS232C (LED) interface adapter available as separate accessory (order code: 01X344201)
DO
CyberScan Waterproof
Handheld
CyberScan DO 300
Dissolved Oxygen/ºC/ºF
Dissolved Oxygen
Designed to meet the rigours of outdoor field measurement, Eutech’s waterproof CyberScan DO 300
is IP67-rated waterproof and even floats on water for easy retrieval. Its galvanic probe requires
no warm-up time, delivers repeatable, stable readings and calls for almost no maintenance.
Back-lit display
for easy reading
in the dark
Waterproof to
IP67 standards
Rubber grips for
firmer grip
Rubber sleeve
protects connector
Galvanic electrode
with built-in ATC and
3 m waterproof cable
Waterproof meter floats
for easy retrieval
• Custom dual-display LCD that shows DO readings (in ppm, mg/L or % saturation) and temperature
readings (in °C and °F)
• Non-volatile memory stores up to 50 data sets with temperature readings
• Auto-compensation of Salinity and Barometric Pressure with manual input
• Independent 100 % and zero adjustment calibrations
• Adjustable backlit display
• GLP-compliant
• Self-diagnostic for easy trouble-shooting
• IP67 waterproof housing
Applications
• Aquaculture (shrimp & catfish farming)
• Ponds and aquariums • Water quality
testing • Water and wastewater treatment
• Recirculating systems and industrial
process systems • Geological and ecological
testing • Monitoring surface and ground
drinking water (in compliance with EPA
regulations) • Schools and laboratories
page | 55
DO
CyberScan Standard
Handheld
CyberScan DO 110
Dissolved Oxygen/ºC/ºF
Accurate with sophisticated yet user-friendly features, the CyberScan DO 110 delivers repeatable,
stable measurements with its unique galvanic electrode – no warm-up time required!
Dissolved Oxygen
Complimentary
CyberComm Data
Acquisition software
Dual-display
with temperature
annunciator
RS232C output allows
direct data transfer
from meter to PC
Ergonomic slim
design for that
perfect palm fit
Adjustable hinge
acts as a table stand
Galvanic electrode
requires no
warm-up time
IP54-rated
housing protects
meter against
water splashes
Applications
Aquacultural: Use to monitor oxygen levels in
catfish and shrimp farming; game stocking
ponds; ornamental fish tanks and ponds;
and in other fish farming applications.
Industrial: Ideal for checks on the quality
of plant water intake and discharge,
wastewater and water treatment, recirculating
systems and industrial process systems.
Environmental: Use to test water quality,
monitor health of aquatic ecosystems,
survey surface and ground water drinking supplies, and meet EPA regulations.
Educational: Ideal for quick, accurate DO
readings in laboratories and schools.
page | 56
• Custom dual-display LCD that shows DO readings in mg/L (ppm) or % saturation and temperature
in °C and °F
• Auto-compensation of Salinity and Barometric Pressure with manual input
• Stores up to 100 data sets with temperature readings
• Direct data transfer via RS232C output – auto data-logging to PC with CyberComm DAS
• Independent 100 % and zero adjustment calibrations
• One-glance monitoring of electrode performance with electrode data display
• Self-diagnostic for easy trouble-shooting
• IP54 splashproof housing
DO
Economy Handheld
DO 6+
Dissolved Oxygen/ºC
Dissolved Oxygen
The Eutech DO 6+ offers high performance at an economical price. Rugged and user-friendly, this
no-frill meter comes with a protective rubber boot and a convenient benchtop stand. Measures in
mg/L (ppm), or % saturation.
Reader-friendly
screen display
Splashproof keypad
IP54-rated housing
protects against dust
and water splashes
Protective rubber boot
• Push-button calibration with auto-buffer recognition for quick and easy calibrations with no mistakes
• Calibration can be performed at 100 % and/or 0 % solution
• Auto-compensation of Salinity and Barometric Pressure with manual input
• Galvanic probe eliminates polarisation delay and delivers quick, stable response
• Non-volatile memory holds meter settings, even when batteries run out
• Hold function freezes readings for easy reference
• Auto-off conserves energy and lengthens battery life-span
• Easy troubleshooting with comprehensive self-diagnostic messages
Applications
• Ponds and aquariums • Aquaculture
(catfish and shrimp farming) • Water and
wastewater treatment • Recirculatng
systems • Industrial process systems
• Water-quality testing • Surface and
ground water testing (meet EPA regulations)
• Ecological studies and monitoring • Field,
laboratory and education institutions
page | 57
DO
Handheld Meters
Specifications
Models
CyberScan Dual-Display
DO 300
DO 600
Eutech Single-Display
DO 6+
DO 110
Dissolved Oxygen
Dissolved
Oxygen
Handheld Meters
Specifications
Measuring Parameter
Highlights
Range
Dissolved
Resolution
Oxygen
Accuracy
Range
% Saturation
Resolution
of Oxygen
Accuracy
Calibration
Range
Temperature Resolution
Accuracy
Range
Salinity
Resolution
Correction
Method
Range
Barometric
Resolution
Pressure
Correction
Method
Probe
Meter
Features
Type
Temperature
Compensation
GLP
Cal-Due Alarm
IP67
Datalogging
Memory
Operating
Temperature
Average/
Stability
LCD Display
Auto-Off
Input
Output
Power
Battery Life
Dimensions Meter
(LxWxH); Weight Boxed
Dissolved Oxygen / ºC / ºF
Waterproof, back-lit display
Waterproof, GLP, RS232C, IrDA
0 to 90.00 mg/L or ppm
±0.20 mg/L
0 to 600.0 %
±2.0 %
0.0 to 60.0 ºC / 32 to 140 ºF
450 to 825 mmHg / 59.9 to 109.9 kPa
Standard handheld, RS232C
0.00 to 19.99 mg/L or ppm
0.01 mg/L or ppm
±1.5 % full scale
0.0 to 199.9 %
0.1 %
±1.5 % full scale
2-point (0 %, 100 %), 1-point (mg/L)
0.0 to 50.0 ºC / 32 to 122 ºF
0.1 ºC / 0.1 ºF
±0.3 ºC / ±0.5 ºF
0.0 to 50.0 ppt
0.1 ppt
Automatic correction after manual input
500 to 1499 mmHg / 66.6 to 199.9 kPa
0.1 mmHg or 0.1 kPa
Automatic correction with
in-built sensor
0.1 ºC
±0.5 ºC
Automatic correction after manual input
Galvanic
ATC / MTC (0.0 to 50.0 ºC)
Yes
–
Yes
–
Yes
Yes
500 data sets
–
–
50 data sets
Yes
100 data sets
–
–
0 to 50 ºC
Yes (selectable)
–
Dot-matrix LCD with backlight
Dual-display LCD with backlight
Dual-display LCD
Single-display LCD
(5.4 x 7.1 cm)
(5.8 x 3.3 cm)
(5.8 x 3.3 cm)
(4.5 x 2.3 cm)
2 to 30 mins after last key pressed
20 mins after last key pressed
DC phono sockets, 6-pin connector
DC socket, 6-pin connector
BNC, 2.5 mm phono socket
IrDA, RS232C (via LED) *
–
RS232C
–
4 x 1.5 V ‘AA’ alkaline batteries or
4 x 1.5 V ‘AAA’ alkaline batteries or
4 x 1.5 V ‘AAA’ alkaline batteries
4 x 1.5 V ‘AAA’ alkaline batteries
9 V DC adapter, 500 mA
9 V DC adapter, 200 mA
> 200 hrs
> 100 hrs
> 700 hrs
18.3 x 9.5 x 5.7 cm ; 460 g
19 x 10 x 6 cm ; 320 g
18 x 9 x 4 cm ; 220 g
15.7 x 8.5 x 4.2 cm ; 255 g
40 x 33 x 10 cm ; 2680 g
40 x 33 x 10 cm ; 2100 g
36 x 28 x 8 cm ; 1555 g
* RS232C (LED) interface adapter available as separate accessory (see page 59 for order information)
page | 58
Dissolved Oxygen / ºC
Economical DO meter
DO
Handheld Meters
Ordering Information
Dissolved Oxygen Handheld Meters
DO 600 / DO 300 / DO 110
DO 600 / DO 300 / DO 110
DO 6+
DO 6+
DO 600
DO 600
DO 600
DO 600 / DO 300 / DO 110 / DO 6
DO 300 / DO 110
DO 300 / DO 110
DO 110
DO 110
ECDOHANDYNEW / ECDOHANDY8M
ECDOHANDYNEW / ECDOHANDY8M
ECDOHANDYNEW
DO6HANDY / ECDO6HANDY3M
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Economy Carry
Kit Set With 4
Sample Bottles
RS232C Cable
CyberScan Carry
Kit Set With 4
Sample Bottles
•
•
•
•
•
•
•
•
•
•
Power Adapter
•
Refilling Electrolyte
•
•
•
•
•
•
•
•
•
•
•
Assembled
Membrane Cap
Housing (x 2)
Assembled
Membrane Cap
Housing
•
CyberComm
Portable
DAS Software
•
•
•
•
•
•
•
•
•
•
Description
Galvanic Dissolved Oxygen electrode, ATC, 7.6 m cable with 1 assembled membrane cap housing,
1 refilling electrolyte & 1 scouring pad
Galvanic Dissolved Oxygen electrode, ATC, 3 m cable with 1 assembled membrane cap housing,
1 refilling electrolyte & 1 scouring pad
Galvanic Dissolved Oxygen electrode, ATC, 3 m cable with 2 assembled membrane cap housing,
1 refilling electrolyte & 1 scouring pad
Galvanic Dissolved Oxygen electrode, ATC, 0.9 m cable 2 assembled membrane cap housing,
1 refilling electrolyte & 1 scouring pad
Order Code
DO6HANDY
01X233913
CyberScan DO 600 series carry kit set – plastic carry case, 4 empty sample bottles (60 ml)
100 / 240 VAC SMPS power adapter, 9 V, 6 W, centre +ve, with US / UK / EUR / Japan plug
RS232C (LED) interface adapter
DO refilling electrolyte (60 ml)
CyberScan neutral carry kit set – plastic carry case, 4 empty sample bottles (60 ml)
Carry pouch for CyberScan handheld
100 / 240 VAC SMPS power adapter, 9 V, 6 W, centre +ve, with US / UK / EUR / Japan plug
RS232C communication cable – 9-pin male to 9-pin female connector, 1 m cable
Assembled membrane cap housing
Membranes & o-rings (pack of 5 units)
Tool for membrane housing
Assembled membrane cap housing
ECWP600DRYKIT
01X030132
91100-85
01X211226
ECWPDRYKIT
ECPOUCH02
60X030130
ECCA02M09F09
15X241402
01X241603
15X241502
01X241608
01X430203
01X030132
01X344202
01X211226
01X266804
56X201400
60X030130
30X219503
15X241402
01X241603
15X241502
01X241608
<< Laboratories
<< Industrial Process Systems
Part No.
ECDOHANDY8M 01X239606
ECDOHANDYNEW 01X239601
ECDO6HANDY3M 01X233916
<< Fish Ponds
page | 59
Dissolved Oxygen
Replacement Electrodes
Used With
•
•
•
•
•
•
•
•
CyberComm 600
DAS Software
01X419503
01X419502
01X262314
01X262307
01X403503
01X403502
01X370113
01X370114
Accessories
0.9 m Cable
DO Electrode
(DO6HANDY)
ECDOWP60042K
ECDOWP60041K
ECDOWP30002K
ECDOWP30001K
ECDO11002K
ECDO11001K
ECDO602PLUSK
ECDO601PLUSK
3 m Cable
DO Electrode
(DO6HANDY3M)
DO 600
DO 600
DO 300
DO 300
DO 110
DO 110
DO 6+
DO 6+
3 m Cable
DO Electrode
(ECDOHANDYNEW)
Part No.
Electrodes
7.6 m Cable
DO Electrode
(ECDOHANDY8M)
Order Code
Temperature
Item
Dissolved Oxygen
Parameters
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