LaMotte SMART 2 - Manual (Page 123)

PROCEDURE
Use COD adapter (see p. 22).
1. Homogenize sample if necessary.
2. Preheat COD heater block to 150±2°C.
3. Remove cap from COD tube. Hold tube at a 45° angle. Use a volumetric
pipet, to carefully add 2.0 mL sample water allowing the sample to run
down the side of the tube.
4. Cap and mix thoroughly.
5. Rinse the outside of the tube with distilled water. Wipe dry with a paper
towel.
6. Repeat steps 3 through 5 using 2.0 mL distilled water. This is the reagent
blank.
7. Place tubes in preheated COD block heater and maintain temperature at
150±2°C for two hours.
8. At the end of the heating period turn the heater off. Wait 20 minutes for
the tubes to cool to 120°C or less.
9. Remove tubes from block heater. Invert several times to mix.
10. Allow to cool to room temperature.
11. Press and hold
ON button until colorimeter turns on.
12. Press
ENTER to start.
13. Press
ENTER to select TESTING MENU.
14. Select ALL TESTS (or another sequence containing 25 COD LR) from
PROGRAMMED TESTS
menu.
15. Scroll to and select 25 COD LR from menu.
16. Wipe the blank tube with a damp towel to remove fingerprints and
smudges. Wipe with a dry towel.
17. Insert reagent blank tube into chamber. Select SCAN BLANK.
18. Remove tube from colorimeter.
19. Insert digested water sample tube into chamber. Select SCAN SAMPLE.
Record result. For the most accurate results, take three readings on each
sample and average the results.
20. Press
OFF
button to turn colorimeter off or press
EXIT
button to exit to
a previous menu or make another menu selection.
Smart2 TEST PROCEDURES 03.05 COD-LR 3/4