Section 5 Bodtrak™ Ii Procedures; General Information - Hach BODTrak II User Manual

Section 5

5.1 General Information

There are three BODTrak II procedure variations. Choose the procedure that meets
the application requirements.
The Simplified procedure
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
recommended for all accuracy and performance checks using seeded GGA. It is
also recommended when test accuracy is important.
The Hach Standard Method procedure
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
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
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
pretreatment.
Use only BODTrak II stir bars and bottles. They are designed specifically for use with the
BODTrak II.
BODTrak™ II procedures
(section 5.2 on page
27). It is possible to use a combination of these procedures
for special considerations including sample seeding and
20) is recommended when sample
(section 5.3 on page
(section 5.4 on page
22) is
24) is recommended
(5.7 on page 33).
19