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Chemical Oxygen Demand High Range
22
• Insert the vials into the reactor and heat them for 2 hours at 150 °C (302 °F).
• At the end of the digestion period switch off the reactor. Wait 20 minutes to allow the vials to cool to
about 120 °C (248 °F).
• Invert each vial several times while still warm, then place them in the test tube rack.
Warning
: The vials are still hot, use caution when handling.
• Leave the vials in the tube rack to cool to room temperature. Do not shake or invert them, the samples
may become turbid.
#1
Blank
#2
Sample
• Select
COD HR
method using the procedure described in the Range Selection section.
• Insert the 16 mm vial adapter using the procedure described in the Using the 16 mm
• Insert the blank vial (#1) into the holder.
• Press
Zero
. The display will show ‑0.0‑ when the meter is zeroed and ready for measurement.
• Remove the vial.
• Insert the sample vial (#2) into the holder.
• Press
Read
to start the reading. The instrument displays the results in
mg/L
of
oxygen (O
2
)
.
INTERFERENCES
Interference may be caused by:
• Chloride above 20000 mg/L, samples with higher chloride concentration should be diluted
#1
#2