EN
High chloride levels will lead to inaccurately high results. See Test Method Technical Information for details. Switching to "M" or "2M" COD Tubetests will increase the suppression of this interference and/or the sample can be diluted prior to the test to reduce the chloride concentration
Turn on heater block and set temperature to 150°C. Note: Timer may need setting above zero for warm up to start.
Take an unused Tubetest and shake to suspend the sediment.
Then, add 2 mL of deionised water.
Replace cap tightly and invert to mix. Warning: Liquid will become hot.
Place in a rack and label the tube as the "Blank".
Take a new, unused, Tubetest and shake to suspend the sediment.
Then, add 2 mL of sample.
Replace cap tightly and invert to mix. Warning: Liquid will become hot.
Set timer on heater block to 120 minutes.
Place both the Blank and the Sample tubes in the heating block.
Ensure safety screen is in position and allow digestion to take place for 120 minutes.
Carefully remove both tubes and invert to mix.
Place in a rack and allow to cool. Ensure any sediment remaining has fully settled.
Fit the Tubetest adapter to Lumiso, then, insert blank and press Blank. Note: Retain blank for future use.
Place the sample tube in the photometer and press Measure to obtain the COD value.
