TEST INSTRUCTIONS - Geotech Environmental Equipment
TEST INSTRUCTIONS - Geotech Environmental Equipment
TEST INSTRUCTIONS - Geotech Environmental Equipment
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INTERFERENCES: Volatile organic compounds are not oxidized to the extent<br />
that they are in the vapor above the digestion solution.<br />
Therefore, they do not contribute to the COD reading.<br />
Chloride concentrations above 10% of COD interfere with<br />
the mercury free tubes. Chloride above 2000 ppm will<br />
interfere with the mercury tubes. Nitrite gives a positive<br />
interference of 1.1 ppm O2 per ppm NO2–N which is<br />
insignificant unless nitrite concentrations are very high.<br />
Other reduced inorganic compounds are stoichiometrically<br />
oxidized, causing a positive interference. Corrections can be<br />
made for these compounds based upon their stoichiometry<br />
and concentrations.<br />
Whenscanningsamplesin16mmtubes,suchasCOD,the<br />
sample chamber lid can not be closed. Use the COD adapter<br />
to minimize stray light interference. To further reduce stray<br />
light interference, do not scan sample in direct sunlight.<br />
COD–Standard Range 2/4 Smart2 <strong>TEST</strong> PROCEDURES 03.05
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