Hach BODTrak II, User Manual

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12.4 Excessive time lag
Refer to Figure 4 on page 18. Curve 3 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. Refer to the Seed the
sample section in the expanded version of this manual for more
information.
Bacteria acclimation also causes conditions that can cause curve 3. This
sometimes occurs with standards and added seed. Add more seed or
select a different seed source.
12.5 Sample temperature
Refer to Figure 4 on page 18. The initial negative results of Curve
4 show that the initial sample temperature was below the specified range
of 20 ±1 ºC. A sample supersaturated with oxygen will also show this
type of curve. Refer to the Sample temperature and Supersaturation
sections in the expanded version of this manual for more information.
12.6 Bottle leak
Refer to Figure 4 on page 18. Curve 5 shows a bottle leak. A bottle leak
makes the system unresponsive. If such a condition occurs, examine the
seal cup and bottle cap for contamination or damage.
Section 13 Replacement parts and accessories
13.1 Replacement parts
Description Quantity Item no.
Bottle, BODTrak II, amber 6 714421
Power cord, 7.5 ft, for North
American 115 VAC use
1 1801000
Power Cord, 8 ft, with continental
European plug for 230 VAC use
1 4683600
Power supply, 115/230 VAC 1 2952500
13.1 Replacement parts (continued)
Description Quantity Item no.
Computer cable for data transfer to
PC
1 2959300
Seal cup 1 2959500
Spatula scoop 1 1225700
Stir bar, magnetic, BODTrak II 1 2959400
13.2 Required reagents
Description Quantity
Item
number
Respirometric BOD nutrient buffer
pillows
1 2962266
Potassium hydroxide pellets 1 31425
13.3 Optional reagents
Description Quantity Item no.
Nitrification inhibitor 35 g 253335
Dispenser cap for 35 g bottle (for
use with nitrification inhibitor)
1 45901
Polyseed inoculum 50 2918700
Potassium iodide solution, 100 g/L 500 mL 1228949
Sodium Hydroxide standard
solution, 1.0 N
900 mL 104553
Sodium Thiosulfate standard
solution, 0.025 N
1000 mL 35253
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