Hach-Lange BODTRACK II User Manual - Manual (Page 16)

Hach Standard Method procedure
Items to collect:
• Thermometer
• BODTrak II bottle
• Blender (optional)
• Graduated cylinder
• Tensette pipet and pipet tips
• Wash water bottle
Required reagents:
• 1 nutrient buffer pillow
• Additional nutrient or buffer (optional)
• Deionized water
Before starting the test:
Use the sample volume table to select the correct sample size
If samples are seeded, prepare a seed blank before a sample is prepared. Treat
the seed blank the same as any other sample and omit step 5.
Refer to Special considerations on page 18 for special considerations.
Use the correct volumes and dilution factor for the BOD range as shown
in
Table 6 .
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 the seed strength is unknown, use 20 mL. Adjust the seed volume as
necessary to achieve optimum results.
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. Select the correct
sample volume for the
BOD range (
Table 6 ).
Measure the sample
into a graduated
cylinder.
4. Add the contents of
1 nutrient buffer pillow
to the graduated
cylinder. 5. If the sample is
seeded, use a tensette
pipet to add the correct
quantity of seed to the
graduated cylinder
(
Table 6 ).
6. If necessary, add
more nutrient or buffer.
Do not add more than a
total volume of 50 mL
(seed, nutrient, buffer).
14 English