Hach BODTrak II User Manual

DOC022.53.90072

BODTrak™ II

USER MANUAL

August 2008,

Edition 1

© Hach Company, 2008. All rights reserved. Printed in China.

3

Table of contents

Section 1 Specifications .................................................................................. 5

Section 2 General information ....................................................................... 7

2.1 Safety information ....................................................................................... 7

2.1.1 Use of hazard information ................................................................ 7

2.1.2 Precautionary labels ......................................................................... 7

2.2 Theory of operation ..................................................................................... 8

2.2.1 Oxygen transfer to sample ............................................................... 8

2.2.2 Pressure sensor function .................................................................. 9

2.2.3 Removing carbon dioxide ................................................................. 9

Section 3 Installation ...................................................................................... 11

3.1 Component list .......................................................................................... 11

3.2 Electrical installation ................................................................................. 12

Section 4 Operation ........................................................................................ 13

4.1 Operational controls .................................................................................. 13

4.1.1 Channel selection keys ................................................................... 14

4.1.2 The arrow keys ............................................................................... 14

4.1.3 The ON key .................................................................................... 14

4.1.4 The OFF key ................................................................................... 14

4.2 Bottle connections .................................................................................... 14

4.3 Setting the clock ....................................................................................... 15

4.4 RS232 Interface ........................................................................................ 15

4.5 Downloading test results ........................................................................... 16

4.5.1 Import data ..................................................................................... 16

4.5.2 Data format ..................................................................................... 17

4.5.3 Printing test results ......................................................................... 18

Section 5 BODTrak™ II procedures .......................................................... 19

5.1 General Information .................................................................................. 19

5.2 Simplified procedure ................................................................................. 20

5.3 Hach GGA (glucose/glutamic acid) procedure .......................................... 22

5.4 Hach Standard Method procedure ............................................................ 24

5.5 Completion steps for all procedures ......................................................... 27

5.5.1 Determination of results .................................................................. 30

5.6 Typical curves ........................................................................................... 32

5.7 Special considerations .............................................................................. 33

5.7.1 Sample dilution ............................................................................... 33

5.7.2 Sample seeding .............................................................................. 33

5.7.3 Sample temperature ....................................................................... 33

5.7.4 Toxic materials ............................................................................... 33

5.7.5 Chlorine .......................................................................................... 34

5.7.6 pH effect ......................................................................................... 34

5.7.7 Supersaturation .............................................................................. 34

Table of contents

4

Section 6 Maintenance ...................................................................................35

6.1 Cleaning the instrument .............................................................................35

6.1.1 Sample bottles ................................................................................35

6.1.2 Stir bars and seal cups ....................................................................35

6.1.3 Bottle fences ...................................................................................35

Section 7 Troubleshooting ............................................................................37

7.1 High oxygen demand .................................................................................38

7.2 Nitrification .................................................................................................38

7.3 Excessive time lag .....................................................................................38

7.4 Sample temperature ..................................................................................38

7.5 Bottle leak ..................................................................................................39

Section 8 Replacement parts and accessories ......................................41

8.1 Replacement parts ....................................................................................41

8.2 Reagents ...................................................................................................41

8.3 Optional reagents ......................................................................................41

8.4 Accessories ...............................................................................................42

Section 9 Contact Information ......................................................................45

5

Section 1 Specifications

Specifications are subject to change without notice.

Table 1 Specifications

General

Range Selectable, 0 to 35, 0 to 70, 0 to 350, 0 to 700 mg/L

Dimensions 28.9 x 26 x 9.8 cm (11

3

/8 x 10 ¼ x 3 7/8 inches)

External power supply

Input: 110 to 240 V, 50/60 Hz, Output: 24 V, UL CSA, and
TUV approved

Capacity Six 492 mL bottles

Shipping weight 4 kg (8.8 lb)

Operating temperature 20 ºC (68 ºF)

Storage temperature 0 to 40 ºC (104 ºF)

Method performance specifications

Precision

On a standard containing 150 mg/L each of glucose and
glutamic acid, a single analyst using 6 BODTrak™ II
instruments and testing 44 samples obtained a mean of
235 mg/L BOD with a 95% confidence limit of distribution
of 11 mg/L or a range of
224 to 246 mg/L BOD.

Drift Less than 3 mg/L BOD in 5 days

Resolution 1 mg/L BOD

Table 2 Certification

Certification

Hach Company certifies this instrument was tested thoroughly, inspected and found to meet
its published specifications when it was shipped from the factory. The BODTrak II has been
tested and is certified as indicated to the following instrumentation standards:

FCC Part 15, Sub-Part B, Class A Limits: Supporting test records by Intellistor, certified
compliance by Hach Company

Canadian Interference-Causing Equipment Regulation, ICES-003, Class A: Supporting
test records by Intellistor, certified compliance by Hach Company

EN 55011/CISPR 11(EMI) “B” Limits per 89/336/EEC EMC: Supporting test records by
Intellistor, certified compliance by Hach Company

EN 50082-1 (Immunity) per 89/336/EEC EMC: Supporting test records by Hach Company,
certified compliance by Hach Company. Standards include:

• IEC 801-2 and EN 61000-4-2 (ESD)

• IEC 801-3 and EN V50140 (RF & EM Field)

• IEC 801-4 and EN 61000-4-4 (Fast Transient)

• EN 61000-4-5 (Surge)

Warranty: US 1 year; EU 2 year

Specifications

6

Radio frequency interference

This Class A digital apparatus meets all requirements of the Canadian Interference-Causing
Equipment Regulations. This device complies with Part 15 of the FCC Rules. Operation is
subject to the following two conditions:

(1) This device may not cause harmful interference, and (2) this device must accept any
interference received, including interference that may cause undesired operation.

Warning
Changes or modifications to this unit not expressly approved by the party
responsible for compliance could void the user’s authority to operate the equipment.

This equipment has been tested and found to comply with the limits for a Class A digital
device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference when the equipment is operated in a
commercial environment. This equipment generates, uses and can radiate radio frequency
energy and, if not installed and used in accordance with the instruction manual, may cause
harmful interference to radio communications. Operation of this equipment in a residential
area is likely to cause harmful interference, in which case the user will be required to correct
the interference at their own expense. Shielded cables must be used with this unit to ensure
compliance with the Class A FCC limits. Because this instrument operates on and
generates radio frequency energy, interference to radio and television reception may occur.
If such interference does occur, the operator should take the necessary steps to correct the
interference. The following techniques of reducing the interference problems are easily
applied:

• Disconnect power from the BODTrak II instrument to verify the instrument is
the source of the interference.

• If the BODTrak II is plugged into the same outlet as the device with which it is
interfering, try another outlet.

• Move the BODTrak II away from the device receiving the interference.

• Reposition the receiving antenna for the device receiving the interference.

• Try combinations of the above.

Table 2 Certification (continued)

7

Section 2 General information

2.1 Safety information

Please read this entire manual before unpacking, setting up or operating this
equipment. Pay attention to all danger and caution statements. Failure to do so
could result in serious injury to the operator or damage to the equipment.

Make sure that the protection provided by this equipment is not impaired, do not
use or install this equipment in any manner other than that specified in this manual.

2.1.1 Use of hazard information

DANGER
Indicates a potentially or imminently hazardous situation which, if not
avoided, will result in death or serious injury.

WARNING
Indicates a potentially or imminently hazardous situation which, if not
avoided, could result in death or serious injury.

CAUTION
Indicates a potentially hazardous situation that may result in minor or
moderate injury.

Important Note: Indicates a situation which, if not avoided, may cause damage to

the instrument. Information that requires special emphasis.

Note: Information that supplements points in the main text.

2.1.2 Precautionary labels

Read all labels and tags attached to the instrument. Personal injury or damage to
the instrument could occur if not observed. A symbol, if noted on the instrument, will
be included with a danger or caution statement in the manual.

This symbol, if noted on the instrument, references the instruction manual for
operation and/or safety information.

Electrical equipment marked with this symbol may not be disposed of in
European public disposal systems after 12 August of 2005. In conformity with
European local and national regulations (EU Directive 2002/96/EC), European
electrical equipment users must now return old or end-of life equipment to the
Producer for disposal at no charge to the user.

Note: For return for recycling, please contact the equipment producer or supplier
for instructions on how to return end-of-life equipment, producer-supplied
electrical accessories, and all auxiliary items for proper disposal.

General information

8

2.2 Theory of operation

Respirometric Biochemical Oxygen Demand (BOD) is a test done at 20 °C (68 °F)
in a controlled environment. The test period can be 5, 7 or 10 days, contingent on
the analysis or protocol. The BOD test measures the quantity of oxygen consumed
by bacteria that oxidize organic matter in a water sample. The test is used to
measure waste loadings at wastewater treatment plants and to examine the
efficiency of wastewater treatment.

BOD test results help find general oxygen uptake patterns. This lets operators
estimate plant operating efficiency and find correct treatment procedures.

Advantages to the BODTrak™ II as an alternative to the dilution method are:

• Minimal time to prepare a sample.

• Decreased total test time.

• The BODTrak II method gives results comparable to the diluton method (BOD5)

in 2 to 3 days.

• Calibration and dissolved oxygen measurement are not necessary.

• The BODTrak II test is easy to monitor.

• The sample is stirred constantly and kept in natural conditions. This makes the

BODTrak II results similar to occurrences found in a natural environment. The
dilution method supplies no additional oxygen to the sample. This causes a
higher percentage of oxygen depletion and possible retardation of biochemical
reactions.

• The BOD can be monitored at any time because the instrument continuously
shows the BOD result. Pressure changes in the closed BODTrak II system are
shown graphically in milligrams per liter (mg/L) on an LCD. The system supplies
360 uniform data points over the selected time period.

• The BODTrak II system continuously removes carbon dioxide from the system
so that the pressure difference monitored is proportional to the quantity of
oxygen used.

• Degassing can cause negative errors when heat is applied to a sample to
achieve experimental temperature. The BODTrak II adjusts for this occurrence.
The BODTrak II does not start the test until the temperature gets to equilibrium.

2.2.1 Oxygen transfer to sample

Bacteria in the sample use oxygen while consuming organic matter in the sample
bottles. The air in the bottle above the sample contains 21% oxygen and
replenishes the dissolved oxygen used by the bacteria. During the test period, stir
bars continually mix the sample in each bottle. This moves oxygen from the air to
the sample and helps simulate natural conditions.

General information

9

2.2.2 Pressure sensor function

The BODTrak II is sealed to prevent external atmospheric pressure changes in the
test bottle. Pressure sensors monitor air pressure in the sample bottles. When
oxygen is consumed, the pressure in the bottle head space drops. The pressure
drop correlates directly to BOD.

2.2.3 Removing carbon dioxide

Carbon dioxide is made when microorganisms oxidize organic matter in the
sample. The carbon dioxide must be removed from the system so it does not
interfere with the measurement. Potassium hydroxide pellets put in the seal cup of
each sample bottle before the test remove the carbon dioxide.

10

11

Section 3 Installation

3.1 Component list

Compare each item below to the items in the shipment. If an item is missing or
damaged, refer to the manufacturer.

• BODTrak™ II instrument

• Power cords, 115 and 230 V

• A UL/CSA approved 115 VAC power cord with a NEMA 5-15P style plug

• A 230 VAC harmonized power cord with a continental European plug

• Power supply, auto–switching between 115 V and 230 V

• 6 seal cups

• 6 BODTrak II amber sample bottles

• 6 BODTrak II magnetic stir bars

• Spatula scoop

• One package nutrient buffer solution pillows

• One container potassium hydroxide pellets

Installation

12

3.2 Electrical installation

The power adaptor supplies AC power to the IEC universal connector (Figure 1).
The power switch powers the instrument on and off.

Figure 1 External connections

1 Power switch 3 RS232 connector
2 IEC universal connector

13

Section 4 Operation

4.1 Operational controls

The BODTrak™ II operator controls are shown in Figure 2.

Figure 2 Operational controls

1 Display 4 ON/OFF keys

1

1

The ON/OFF keys start and stop a test. They do not power the instrument on and off.

2 Channel selection keys 5 Power indicator
3 Arrow keys

Operation

14

4.1.1 Channel selection keys

Push the related channel selection key to show data for one of the 6 bottles.

The channel selection keys are also used in the instrument setup menu to choose a
parameter to be edited (Table 3).

4.1.2 The arrow keys

The display shows a graph of BOD values on the vertical axis and time in days on
the horizontal axis. Push the left and right arrow keys to move the cursor along the
BOD curve to show the approximate coordinates (time, BOD) of the selected data
point.

The time interval and BOD value of the data point are shown in the lower right of
the display. The cursor is automatically placed at the most recently collected data
point in a channel display.

Push and hold the two arrow keys at the same time to go into the instrument setup
menu. The arrow keys are also used to change the time, date, test length and
range.

4.1.3 The ON key

To access the range selection menu, push the ON key from a channel display
screen. Then push and hold the ON key to start the test for the selected channel.

4.1.4 The OFF key

When a test is in DELAY or RUN modes, pushing and holding the OFF key
manually ends the test. The instrument will display END. The OFF key is also used
to exit the instrument setup menu or range selection menu. Any changes made
prior to exit will be saved.

4.2 Bottle connections

Each bottle position/channel has the applicable tube numbered with a plastic
sleeve. The bottle positions are numbered 1 though 6 with number 1 in the back left
corner of the chassis. Use the channel selection keys as a guide.

Table 3 Channel key setup parameters

Channel Parameter

1 Year (0-99)
2 Month (1-12)
3 Day (1-31)
4 Hour (0-24)
5 Minute (0-59)
6 Test Length (5, 7, or 10 days)

Operation

15

4.3 Setting the clock

All channels must show END or CLEAR before the clock can be set. Push and hold
the two arrow keys at the same time until the instrument setup menu is shown.
Select the clock parameter to be adjusted by pushing the applicable channel key
(Table 3 on page 14). Use the arrow keys to edit the chosen parameter. Adjust
each parameter in the same manner. When all time adjustments are complete,
push the OFF key to save and go back to the data display screen.

4.4 RS232 Interface

All RS232 connections are made through the Serial I/O port (Figure 1 on page 12).
Connect the 9-pin D connector of a computer interface cable to the Serial I/O port
on the instrument. Connect the opposite end of the cable to the computer Serial I/O
port (Com 1 or Com 2).

The BODTrak II instrument is equipped as Data Communication Equipment (DCE).
The BODTrak II operates at 9600 baud with 8 data bits, no parity and one stop bit.
The computer or printer will not receive complete transmissions if the device cannot
continuously receive at 9600 baud.

Note: Use of the specified cable or an equivalent shielded cable is mandatory to meet Radio
Frequency Emissions requirements.

Operation

16

4.5 Downloading test results

To transfer test results to a PC:

1. Choose PROGRAMS, ACCESSORIES, COMMUNICATIONS, HYPERTERMINAL.

2. In the Connection Description window, type in a name for the connection and

choose an icon to represent it. Click

OK.

3. In the Connect To window, use the drop-down menu to choose the COM port

connected to the BODTrak II instrument. Click OK.

4. Configure the COM port properties:
BPS = 9600, Data Bits = 8, Parity = None, Stop Bits = 1,
Flow Control = None.

5. Click

OK. The connect indicator will be shown.

6. Choose TRANSFER, CAPTURE TEXT.

7. In the Capture Text window, click

BROWSE to choose a specific save location.

Name the file and click SAVE.

8. In the Capture Text window click

START.

9. Power on the BODTrak II. Push the applicable channel key for the data to be

downloaded.

10. Type GA in the HyperTerminal window, then push

ENTER. The transfer is

complete when the screen stops adding new data.

11. Choose

TRANSFER, CAPTURE TEXT, STOP.

12. Choose CALL, DISCONNECT. The disconnected indicator will be shown.

13. To end the HyperTerminal session, choose

FILE, EXIT.

14. Click

YES to save the session and all instrument/port configuration settings.

4.5.1 Import data

To import the data from the captured text file:

1. Open a new or existing spreadsheet. Choose DATA, IMPORT EXTERNAL DATA,

IMPORT DATA.

2. Select the text file captured in HyperTerminal. Click

IMPORT.

3. In the Text Import Wizard, choose Delimited as the file type, the start row in
the spreadsheet, and Windows (ANSI) as the file origin. Click

NEXT.

4. Check the Space delimiter and Treat consecutive delimiters as one check

boxes. Click

NEXT.

5. Choose General as the Column data format then click FINISH.

6. In the Import Data window, choose Existing worksheet. Choose the starting cell

then click

OK. The data will appear in your spreadsheet.

7. Choose File, Save As to save the spreadsheet.

The spreadsheet data cannot be edited or formatted in HyperTerminal or with the
BODTrak II.

Operation

17

4.5.2 Data format

When a result array is downloaded to HyperTerminal, all data from the test are sent
without pause. The data flow cannot be stopped or paused.

Figure 3 shows channel number, start date, start time, and the format of the

downloaded data. BOD values in mg/L follow. Only the first data points, of a
maximum of 360 equal distance points, are shown in this example. Each line ends
with a carriage return and a line feed. The end of the data stream is shown by a
message such as “Test Run to Completion” and a dollar symbol ($).

If small negative BOD values are seen at the start of a test, refer to Troubleshooting

on page 37.

BOD Log for Ch 1
Status: END
Full Scale: 700 mg/L
Tst length: 7 days
Start Date: 3/3/08
Time: 13:04

Days, Reading (mg/L)

0.00, 0

0.05, 10

0.11, 12

0.16, 12

0.22, 14

0.27, 14

0.33, 12

0.38, 8

0.44, 10

0.50, 12

0.55, 12

0.61, 14

-

-

­Test Run to Completion
$

Figure 3 Downloaded test data

Operation

18

4.5.3 Printing test results

The BODTrak II is compatible with the Citizen PD-24 printer, which is available as
an optional accessory (Section 8 on page 41). Connect the printer cable to the
serial port on the BODTrak II using the gender adapter provided with the printer.
Make sure the printer interface settings are correct (section 4.4 on page 15).

Power on the BODTrak II instrument. Push and hold the applicable channel number
for approximately 5 seconds at any time during a test. This moves the test results
from the BODTrak II to the printer. The instrument will send a copy of the graphical
display and a truncated data stream (127 data points).

19

Section 5 BODTrak™ II procedures

5.1 General Information

There are three BODTrak II procedure variations. Choose the procedure that meets
the application requirements.

The Simplified procedure (section 5.2 on page 20) is recommended when sample
seeding, extra nutrients or buffers are not necessary. It is also recommended when
accuracy requirements are not stringent.

The Hach GGA (glucose/glutamic acid) procedure (section 5.3 on page 22) is
recommended for all accuracy and performance checks using seeded GGA. It is
also recommended when test accuracy is important.

The Hach Standard Method procedure (section 5.4 on page 24) is recommended
when samples are seeded or extra nutrients or reagents are added. Use this
procedure when following Standard Methods for the Examination of Water and
Wastewater, 21st Edition, Method 5210 D Respirometric Method.

All procedure variations are followed by completion steps for all procedures
(section 5.5 on page 27). It is possible to use a combination of these procedures
with one instrument, but in different bottles. Only one test length can be chosen.

Before starting the test:

Use the applicable sample volume tables for each procedure.

If power is interrupted when the instrument is in DELAY status, the test will stop and the
status will change to CLEAR when power returns. Start the test again.

If power is interrupted when the instrument is in RUN status, the test will resume when
power returns.

Keep deionized water overnight in an incubator at 20 ºC. Shake the deionized water to
saturate with air.

Settle the seed overnight in the BOD incubator at a temperature of 20 ºC. Be careful not to
disturb the settled solution. Pipet seed solution from the top.

Dilution is necessary if samples have BOD values more than 700 mg/L (5.7 on page 33).

At elevations higher than 5000 feet above sea level the 0 to 35 mg/L BOD range is
decreased to 0 to 25 mg/L BOD. Adjustment is not necessary for other test ranges.

Refer to section 5.7 on page 33 for special considerations including sample seeding and
pretreatment.

Use only BODTrak II stir bars and bottles. They are designed specifically for use with the
BODTrak II.

BODTrak™ II procedures

20

5.2 Simplified procedure

Required apparatus:

BODTrak II bottle

Thermometer

Blender (optional)

Graduated cylinder

Required reagents:

2 nutrient buffer pillows

Table 4 Simplified sample volumes

BOD range mg/L Sample volume mL

0 to 35 420

0 to 70 355
0 to 350 160
0 to 700 95

1. Heat or cool the
sample to 19 to 21 ºC
(66 F to 70 ºF).

2. Homogenize the
sample in a blender if it
contains large settleable
or floatable solids.

3. Choose the correct
sample size for the
sample range (Table 4).
Measure the sample into a
graduated cylinder.

BODTrak™ II procedures

21

4. Add the contents of 2

nutrient buffer pillows to
the graduated cylinder.

5. Transfer the contents of
the graduated cylinder to
a BODTrak II bottle.
Repeat steps 1 to 5 for
additional samples.

6. Continue to the
completion steps for all
procedures (section 5.5

on page 27).

BODTrak™ II procedures

22

5.3 Hach GGA (glucose/glutamic acid) procedure

Required apparatus:

BODTrak II bottle

Graduated cylinder

Volumetric pipet and pipet filler

Tensette® pipet and pipet tips

Wash water bottle

Ampule breaker

Required reagents:

Deionized water

Hach GGA solution

2 nutrient buffer pillows

Before starting the test:

Use Hach BOD Standard Solution Ampules for Manometric Method (3000 mg/L Glucose,
3000 mg/L Glutamic acid).

On a standard containing 150 mg/L each of glucose and glutamic acid, a single analyst
using 6 BODTrak II instruments and testing 44 samples obtained a mean of 235 mg/L BOD
with a 95% Confidence Limit of Distribution of 11 mg/L or a range of 224 to 246 mg/L BOD
after 5 days.

Always prepare the seed blank before the GGA samples. Use the same amount of seed for
all GGA samples and seed blank.

Refer to section 5.7 on page 33 for special considerations.

Prepare seed blank

Use steps 1, 3 to 7.

Prepare sample

Use steps 1 to 7.

BODTrak™ II procedures

23

Table 5 GGA sample volumes

BOD range

(mg/L)

GGA volume

(mL)

Seed volume

(mL)

Final Volume

(mL)

0 to 350 8.0 10 to 35 160

Note: If seed strength is unknown, use 20 mL. Adjust seed volume as necessary to achieve
optimum GGA results. Use the same amount of seed for all GGA samples and seed blank.

1. Add approximately
30 mL of deionized water
to a 200 mL graduated
cylinder.

2. Use a volumetric pipet
to transfer 8.0 mL of Hach
GGA solution to the
graduated cylinder.

Note: Skip this step when
preparing the seed blank.

3. Add the contents of 2
nutrient buffer pillows to
the graduated cylinder.

4. Use a tensette pipet to
add the correct quantity of
seed to the graduated
cylinder (Table 5).

5. Dilute to the sample to
160 mL using a deionized
water wash bottle.

6. Transfer the prepared
sample from the
graduated cylinder to a
BODTrak II bottle.

Note: For additional GGA
samples, repeat steps 1 to 6.

7. Continue to the
completion steps for all
procedures (section 5.5

on page 27).

BODTrak™ II procedures

24

5.4 Hach Standard Method procedure

Required apparatus:

Thermometer

BODTrak II bottle

Blender (optional)

Graduated cylinder

Tensette pipet and pipet tips

Wash water bottle

Required reagents:

2 nutrient buffer pillows

Additional nutrient or buffer (optional)

Deionized water

Before starting the test:

Use the sample volume table to choose the correct sample size (Table 6).

If seeding samples, prepare a seed blank before preparing a sample. Treat the seed blank
the same as any other sample and omit step 5.

Refer to section 5.7 on page 33 for special considerations.

Table 6 Hach Standard Method sample volumes

BOD range

(mg/L)

Sample

volume (mL)

Seed volume

(mL)

Final volume

(mL)

Dilution

factor

0 to 35 370 10 to 35 420 1.14

0 to 70 305 10 to 35 355 1.16
0 to 350 110 10 to 35 160 1.45
0 to 700 45 10 to 35 95 2.11

Note: If seed strength is unknown, use 20 mL. Adjust seed volume as necessary to achieve
optimum results.

BODTrak™ II procedures

25

1. Heat or cool the

sample to 19 to 21 ºC
(66 to 70 ºF).

2. Homogenize the
sample in a blender if it
contains large settleable
or floatable solids.

3. Choose the correct
sample size for the
sample range (Table 6 on

page 24). Measure the

sample into a graduated
cylinder.

4. Add the contents of 2
nutrient buffer pillows to
the graduated cylinder.

5. If seeding the sample,
use a tensette pipet to add
the correct quantity of
seed to the graduated
cylinder (Table 6 on page

24).

6. If necessary, add more
nutrient or buffer. Do not
add more than a total
volume of 50 mL (seed,
nutrient, buffer).

BODTrak™ II procedures

26

7. Fill to the final test

range volume, if
necessary, with a
deionized wash water
bottle (Table 6 on page

24).

8. Transfer the prepared
sample from the
graduated cylinder to a
BODTrak II bottle.

Note: Repeat steps 1 to 8 for
additional samples.

9. Continue to the
completion steps for all
procedures (section 5.5

on page 27).

BODTrak™ II procedures

27

5.5 Completion steps for all procedures

Required apparatus:

BODTrak II

Spatula scoop

BOD incubator

Seal cup

Stir bar

Required reagents:

2 potassium hydroxide pellets

1. Put a BODTrak II stir
bar into the bottle.

2. Put a seal cup into the
neck of the bottle.

3. Use a spatula scoop
to add 2 potassium
hydroxide pellets to the
seal cup. Repeat steps
1 to 3 for each sample
bottle.

BODTrak™ II procedures

28

4. Put the bottles on the

BODTrak II chassis.
Connect the applicable
tube to the sample bottle
and tighten the cap.

5. Put the instrument in
the incubator. The
incubator temperature
must be 20 ± 1 ºC
(68 ± 1 ºF).

Note: Instrument
performance has not been
tested at other
temperatures.

6. Plug in and power on
the instrument. Make
sure all stir bars are
rotating. If not, lift the
bottle up and set down
again.

7. Push and hold the left
and right arrow keys at
the same time to access
the instrument setup
menu.

Note: Set the time and date,
if necessary (section 4.3 on

page 15).

8. Push the Channel 6
key to access the test
length parameter. Use
the arrow keys to choose
a 5, 7 or 10 day test.

Note: The selected test
length is for all 6 channels.

9. Push OFF to save
selections and exit the
menu.

BODTrak™ II procedures

29

10.To start the test, push

the channel number
applicable to the bottle.

11.Push the

ON key. The

range selection menu is
shown.

12.Use the arrow keys to
choose the test range.

Note: Use the left arrow key
for the 0 to 35 and
0 to 70 mg/L ranges. Use
the right arrow key for the
0 to 350 and 0 to 700 mg/L
ranges.

13.Push and hold the ON
key to start a test. A
graph will be displayed.

Note: To cancel a test push
and hold the OFF key.

Note: There is a built-in
1 hour instrument/sample
equilibration period before
data collection. The display
will show DELAY during this
period.

14.Do steps 10 through
13 again to set the test
range and start each of
the 6 channels. It is not
necessary to operate all
6 channels if less than 6
samples are available.

BODTrak™ II procedures

30

5.5.1 Determination of results

After the end of the chosen test period (5, 7 or 10 days), END is shown on the
display. The procedure that is done dictates the determination of the results. The
results are determined based on the selected procedure: Simplified, Hach GGA or
Hach Standard Method.

5.5.1.1 Simplified sample results

The Simplified Procedure results are shown on the BODTrak II display. Push the
applicable channel selection key to show the results.

Note: If the sample was pre-diluted, apply a dilution factor to the instrument reading
(section 5.7.1 on page 33).

5.5.1.2 Hach GGA (glucose/glutamic acid) results

The seed blank and seeded GGA sample results are necessary for the Hach GGA
procedure results.

1. Push the channel selection key for the seed blank bottle. The results are
shown.

2. Push the channel selection key for the seeded GGA sample bottle. The results
are shown.

3. Calculate the results:
BOD mg/L = seeded GGA sample result - seed blank result

5.5.1.3 Hach Standard Method results

1. Push the channel selection key for the Hach Standard Method sample bottle.

The results are shown.

Note: Treat the seed blank the same as all other samples.

Note: If the sample was pre-diluted, apply a dilution factor to the instrument reading

(section 5.7.1 on page 33).

2. Find the dilution factor based on the selected range (Table 6 on page 24).

Example: If the sample range selected was 0 to 350 mg/L BOD, the dilution

factor is 1.45.

3. Calculate the corrected results:
BOD mg/L = BOD mg/L (instrument reading) x dilution factor

Example:
Instrument Reading = 200 mg/L, BOD dilution factor = 1.45
200 mg/L x 1.45 = 290 mg/L BOD (Corrected Result)

BODTrak™ II procedures

31

4. When samples are seeded, calculate the results using this equation and the

corrected results:

Where:

A = corrected BOD of the seeded sample
B = corrected BOD of the seed blank
SA = volume of seed in sample (sample can also be GGA)
SB = volume of seed in seed blank

Example:
A= 290 mg/L BOD
B= 120 mg/L BOD
SA= 20 mL
SB= 110 mL

BOD mg/L = 268 mg/L

BOD mg/L()ABx

SA
SB

--------

⎝⎠

⎛⎞

–=

BOD mg/L()290mg/L 120mg/L x

20mL

110mL

-------------------

⎝⎠

⎛⎞

–=

BODTrak™ II procedures

32

5.6 Typical curves

Typical curves through a 10 day test period are shown in Figure 4. For incorrect
curves refer to Figure 5 on page 37.

Figure 4 Typical curves

1 Typical with substrate variation 3 Typical with time lag
2 Typical

BODTrak™ II procedures

33

5.7 Special considerations

5.7.1 Sample dilution

Unknown sample BOD effluent is typically in the 0 to 70 mg/L range. Unknown
sample BOD influent is typically in the 0 to 700 mg/L range. When the oxygen
requirement of a sample is more than 700 mg/L, dilute the sample with high-quality
distilled or deionized water.

Calculate the results to include the additional dilution factor. Example: If the BOD of
the sample is 1000 mg/L, dilute the sample 1:1 with distilled or deionized water. The
estimated BOD is now 500 mg/L. Use the sample volume specified in the table for
the 0 to 700 mg/L range of the chosen procedure. Multiply the instrument reading
result by 2. If using the Hach Standard Method procedure, continue with remaining
calculations.

5.7.2 Sample seeding

Some types of BOD samples do not contain sufficient bacteria to oxidize the
organic matter in the sample. Many industrial wastes are of this type. Some sewage
treatment plant effluents are chlorinated and essentially sterile. A BOD test cannot
be done in the absence of viable bacteria. To test such samples, seed each bottle
from a source known to contain a viable bacterial population.

Settled domestic wastewater plant influent or primary clarifier effluent are the
preferred sources of seed for most samples. Mixed liquor or undisinfected effluent
can be used for seed, but it is recommended to include a nitrification inhibitor.
Commercial seed sources are sometimes suitable. To prepare, see the instructions
from the manufacturer.

5.7.3 Sample temperature

Standard Methods for the Examination of Water and Wastewater, 21st Ed., 2005,
5210 D recommends an incubation temperature of 20 ±1 °C (68 °F) for the BOD
test. Put the BODTrak II instrument in an incubator that is adjusted to 20 ±1 °C. An
applicable BOD incubator is available from Hach (section 8.1 on page 41). Warm or
cool samples to 20 ± 1 °C.

Note: Instrument performance has not been validated at temperatures other than 20 °C.

5.7.4 Toxic materials

Industrial and chlorinated samples often contain toxic substances and require
special considerations when running BOD tests. Toxic materials in the sample will
cause decreased BOD values. Dilute the sample to minimize the toxic materials or
their effects. Refer to Standard Methods for the Examination of Water and
Wastewater, 21st edition, 5210 D.

BODTrak™ II procedures

34

5.7.5 Chlorine

Any chlorine in the sample must be removed prior to testing. Keep the sample at
room temperature for 1 to 2 hours before a test to dissipate low chlorine
concentrations. If any chlorine remains after sitting for 2 hours or if the chlorine
concentration is high, add sodium thiosulfate to remove the chlorine:

1. In a 250 mL erlenmeyer flask add 100-mL of sample.

2. Add 10 mL of 100 g/L potassium iodide solution and

10 mL of 0.02 N sulfuric acid standard solution to the erlenmeyer flask.

3. Add 3 droppers of starch indicator solution and swirl to mix.

4. Titrate from dark blue to colorless with 0.025 N Sodium Thiosulfate standard

solution.

5. Calculate the quantity of sodium thiosulfate standard solution necessary to
dechlorinate the remaining sample:

6. Add the necessary quantity of 0.025 N sodium thiosulfate standard solution to
the sample and mix fully. After 10 to 20 minutes, do the BOD test.

5.7.6 pH effect

Low BOD test results occur when sample pH is outside the range of 6 to 8. Keep
this pH to simulate source sample conditions or adjust the pH to neutrality (buffered
at pH 7). Use 1.0 N (or weaker) sulfuric acid to neutralize caustic samples. Use 1.0
N (or weaker) sodium hydroxide to neutralize acidic samples. When samples are
pH adjusted, they should also be seeded.

5.7.7 Supersaturation

Equilibrate supersaturated cold samples (containing more than 9 mg/L dissolved
oxygen at 20 °C) to saturation:

1. Heat or cool the sample temperature to approximately 20 °C.

2. Half fill a sample bottle with sample.

3. Shake for 2 minutes or aerate with filtered compressed air for 2 hours.

mL of Sodium Thiosulfate

mL used()mL sample to be dechlorinated()

100

-------------------------------------------------------------------------------------------------------------------

=

35

Section 6 Maintenance

DANGER
Only qualified personnel should conduct the tasks described in this section
of the manual.

6.1 Cleaning the instrument

Clean spills on the BODTrak™ II instrument with a soft cloth which has been
dampened with deionized or distilled water.

6.1.1 Sample bottles

After each test, empty the sample bottles and flush them thoroughly with hot water.
Use a brush, hot water and soap to remove residue. Residue creates a BOD. Flush
the bottles thoroughly with tap water and finally with distilled or deionized water to
remove all detergent.

6.1.2 Stir bars and seal cups

Clean the stir bars with hot water and soap. Use a brush to remove deposits. Flush
with tap water and finally with distilled or deionized water to remove all detergent.
Carefully empty and rinse the seal cups with water. Invert to dry.

6.1.3 Bottle fences

The bottle fences prevent tipping of the bottles and provide tubing management
during storage. For storage, put the tubing into the opening in the bottle fence.
Wind the tubing counter-clockwise and secure the bottle cap inside the fence.

36

37

Section 7 Troubleshooting

Incorrect BOD curves through a 10 day test period are shown in Figure 5. For
typical curves refer to Figure 4 on page 32.

Figure 5 Incorrect BOD curves

1 High oxygen demand 4 Initial sample temperature below

20 ºC or supersaturated with
oxygen

2 Nitrification 5 Bottle leak
3 Excessive time lag

Troubleshooting

38

7.1 High oxygen demand

Samples that are above range (for example, a BOD over 350 mg/L when a 160-mL
sample is taken) will cause results as shown in Curve 1 (Figure 5 on page 37).
Dilute the sample (section 5.7 on page 33) or use a higher BOD range and a
different sample volume (Table 4 on page 20, Table 5 on page 23 or Table 6 on

page 24).

When the BOD range of a sample is unknown:

• Use the results from the Chemical Oxygen Demand (COD) test. An estimated
BOD value can be obtained by multiplying the COD by 0.68.

• Use the results from a series of BOD tests using the same sample but different
volumes.

• Or use dilution ratios to choose an applicable BOD range.

Typically, effluent is in the 0-70 mg/L range while influent is in the 0-700 mg/L
range. When the BOD of the sample is more than 700 mg/L, prepare a sample
dilution (section 5.7 on page 33).

7.2 Nitrification

The condition shown by Curve 2 is an example of nitrification (Figure 5 on page

37). Deviation from the typical curve (shown as the dashed line) is apparent by the

concave increase near the end of the test period.

Biological oxidation of organic nitrogen usually occurs after 5 days with typical
domestic waste. Nitrifying bacteria develop more slowly than other types of
bacteria.

However, some samples contain a high concentration of nitrifying bacteria and
nitrification results can occur sooner. Control nitrification problems with Hach
Nitrification Inhibitor. Dispense the inhibitor powder into an empty sample bottle and
then add the sample. With the Hach Dispenser cap, dispense 6 shots
(approximately 0.48 grams) into the empty bottle. Refer to replacement parts and
accessories (Section 8 on page 41).

7.3 Excessive time lag

Curve 3 (Figure 5 on page 37) shows a test that did not start with sufficient bacteria
during the incubation period. To do a test on a sample without sufficient bacteria,
seed the sample (section 5.7.2 on page 33).

Bacteria acclimation also causes conditions that could cause Curve 3. This
sometimes occurs with standards and added seed. Add more seed or choose a
different seed source.

7.4 Sample temperature

The initial negative results of Curve 4 (Figure 5 on page 37) show that the initial
sample temperature was below the specified range of 20 ± 1 ºC. A sample
supersaturated with oxygen will also display this type of curve (section 5.7.3 on

page 33 and section 5.7.7 on page 34).

Troubleshooting

39

7.5 Bottle leak

Curve 5 (Figure 5 on page 37) shows a bottle leak. A bottle leak can also cause no
response from the system. If such a response occurs, check the seal cup and bottle
cap for contamination or damage.

40

41

Section 8 Replacement parts and

accessories

8.1 Replacement parts

Description Quantity Item Number

BODTrak™ Instrument, 115/230 VAC 1 2952400

Bottle, BODTrak II, amber (6x) 1 714421

Power cord, 18/3 SVT 7.5’, 10A-125 VAC for North
American 115 VAC use

1 2959200

Power Cord, 8’, with continental European plug for 230
VAC use

1 2959100

Power Supply 1 2952500

Seal Cup 1 2959500

Spatula scoop 1 1225700

Stir Bar, magnetic, BODTrak II 1 2959400

8.2 Reagents

Description Quantity Item Number

BOD nutrient buffer pillows for preparing 300 mL (50x) 1 1416066

Potassium hydroxide pellets 1 31425

8.3 Optional reagents

Description Quantity Item Number

Nitrification inhibitor, 35 g 1 253335

Dispenser cap for 35 g bottle (for use with nitrification
inhibitor)

1 45901

Polyseed Inoculum (50x) 1 2918700

Potassium iodide solution, 100 g/L, 500 mL 1 1228949

Sodium Hydroxide standard solution, 1.0 N,
900 mL

1 104553

Sodium Thiosulfate standard solution, 0.025 N, 1000
mL

1 35253

Starch indicator solution, dropping bottle,
100 mL MDB

1 34932

Sulfuric acid, ACS, 500 mL 1 97949

Sulfuric acid, 0.02 N standard solution, 1000 mL 1 20353

42

Sulfuric acid, 1.0 N standard solution,
1000 mL

1 127053

Voluette ampule standard for BOD, 3000 mg/L for
manometric, 10-mL/ampule, 16 ampules

1 1486610

8.4 Accessories

Description Quantity Item Number

Ampule breaker kit for voluette ampules 1 2196800

Bottle, wash, 500 mL 1 62011

Bottle, polyethylene, with spigot, 4 L 1 1486817

Brush, cylinder, size 2 1 68700

Buret, straight stopcock, Teflon plug, 25 mL 1 1405940

Clamp, buret, double 1 32800

Computer cable for data transfer to PC 1 2959300

Cylinder, graduated, 10 mL 1 50838

Cylinder, graduated, 25 mL 1 50840

Cylinder, graduated, 50 mL 1 50841

Cylinder, graduated, 100 mL 1 50842

Cylinder, graduated, 250 mL 1 50846

Cylinder, graduated, 500 mL 1 58049

Cylinder, graduated, 1000 mL 1 50853

Flask, erlenmeyer 1 50546

Incubator, BOD, Model 205, 110 V 1 2616200

Incubator, BOD, Model 205, 220/240 V 1 2616202

Pipet, Tensette

®

, 0.1 to 1.0 mL 1 1970001

Pipet, Tensette, 1 to 10 mL 1 1970010

Pipet tips, 0.1 to 1.0 mL (50x) 1 2185696

Pipet tips, 0.1 to 1.0 mL (1000x) 1 2185628

Pipet tips, 1 to 10 mL (50x) 1 2199796

Pipet tips, 1 to 10 mL (250x) 1 2199725

Pipet filler, 3 valve 1 1218900

Pipet, serological, glass, 10 mL 1 53238

Printer, Citizen PD-24 with cable 1 2960100

Standard Methods for the Examination of Water and
Wastewater

1 2270800

Support stand, buret 1 32900

8.3 Optional reagents (continued)

Description Quantity Item Number

Replacement parts and accessories

43

Thermometer, Mercury, -20 to 110 °C 1 56601

Thermometer, non-Mercury, -20 to 110 °C 1 2635702

Water Still, 120 V 1 2615900

Water Still, 220 V 1 2615902

Water System, Ultrapure, Millipore Direct -Q 3 1 2512100

DQ3 purification pack 1 2512201

8.4 Accessories (continued)

Description Quantity Item Number

44

45

Section 9 Contact Information

HACH Company World
Headquarters

P.O. Box 389
Loveland, Colorado
80539-0389 U.S.A.
Tel (800) 227-HACH
[phone]
(U.S.A. only)
Fax [phone]
[e-mail]
www.hach.com

Repair Service in the
United States:

HACH Company
Ames Service
100 Dayton Avenue
Ames, Iowa 50010
Tel [phone]
(U.S.A. only)
Fax [phone]

Repair Service in
Canada:

Hach Sales & Service
Canada Ltd.
1313 Border Street, Unit 34
Winnipeg, Manitoba
R3H 0X4
Tel [phone]
(Canada only)
Tel [phone]
Fax [phone]
[e-mail]

Repair Service in Latin
America, the Caribbean,
the Far East, Indian
Subcontinent, Africa,
Europe, or the Middle
East:

Hach Company World
Headquarters,
P.O. Box 389
Loveland, Colorado,
80539-0389 U.S.A.
Tel [phone]
Fax [phone]
[e-mail]

HACH LANGE GMBH

Willstätterstraße 11
D-40549 Düsseldorf
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.de

HACH LANGE LTD

Pacific Way
Salford
GB-Manchester, M50 1DL
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.co.uk

HACH LANGE LTD

Unit 1, Chestnut Road
Western Industrial Estate
IRL-Dublin 12
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.ie

HACH LANGE GMBH

Hütteldorferstr. 299/Top 6
A-1140 Wien
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.at

DR. BRUNO LANGE AG

Juchstrasse 1
CH-8604 Hegnau
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.ch

HACH LANGE FRANCE
S.A.S.

33, Rue du Ballon
F-93165 Noisy Le Grand
Tél. [phone]
Fax [phone]
[e-mail]
www.hach-lange.fr

HACH LANGE SA

Motstraat 54
B-2800 Mechelen
Tél. [phone]
Fax [phone]
[e-mail]
www.hach-lange.be

DR. LANGE NEDERLAND
B.V.

Laan van Westroijen 2a
NL-4003 AZ Tiel
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.nl

HACH LANGE APS

Åkandevej 21
DK-2700 Brønshøj
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.dk

HACH LANGE AB

Vinthundsvägen 159A
SE-128 62 Sköndal
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.se

HACH LANGE S.R.L.

Via Riccione, 14
I-20156 Milano
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.it

Contact Information

46

HACH LANGE S.L.U.

Edif. Arteaga Centrum
C/Larrauri, 1C- 2ª Pl.
E-48160 Derio/Vizcaya
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.es

HACH LANGE LDA

Av. do Forte nº8
Fracção M
P-2790-072 Carnaxide
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.pt

HACH LANGE SP.ZO.O.

ul. Opolska 143 a
PL-52-013 Wrocław
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.pl

HACH LANGE S.R.O.

Lešanská 2a/1176
CZ-141 00 Praha 4
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.cz

HACH LANGE KFT.

Hegyalja út 7-13.
H-1016 Budapest
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.hu

HACH LANGE S.R.L.

Str. Leonida, nr. 13
Sector 2
RO-020555 Bucuresti
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.ro

HACH LANGE

8, Kr. Sarafov str.
BG-1164 Sofia
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.bg

HACH LANGE SU
ANALİZ SİSTEMLERİ
LTD. ŞTİ.

Hilal Mah. 75. Sokak
Arman Plaza No: 9/A
TR-06550 Çankaya/ANKARA
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.com.tr

HACH LANGE D.O.O.

Fajfarjeva 15
SI-1230 Domžale
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.si

ΗΑCH LANGE E.Π.Ε.

Αυλίδος 27
GR-115 27 Αθήνα
Τηλ. [phone]
Fax [phone]
[e-mail]
www.hach-lange.gr

HACH LANGE E.P.E.

27, Avlidos str
GR-115 27 Athens
Tel. [phone]
Fax [phone]
[e-mail]
www.hach-lange.gr