LaMotte COD Plus Colorimeter 1922-EX2 - Manual (Page 77)

PROCEDURE
1. Press and hold
ON button until colorimeter turns on.
2. Press
ENTER to start.
3. Press
ENTER to select TESTING MENU.
4. Select All Tests (or another sequence containing 8 Cobalt) from
TESTNG MENU
.
5. Scroll to and select 8 Cobalt from menu.
6. Rinse a tube (0290) with sample water. Fill to 10 mL with sample.
7. Insert the tube into chamber, close lid and select SCAN BLANK.
8. Remove the tube from colorimeter.
9. Use the 1.0 mL pipet (0354) to add 1 mL of *Cobalt Buffer (4852). Cap
and mix.
10. Use the other 1.0 mL pipet (0354) to add 1 mL of *Cobalt Indicator
Reagent (4853). Cap and mix.
11. Wait 3 minutes.
12. Use the 0.5 mL pipet (0353) to add 0.5 mL *Stabilizer Solution (4854).
Cap and invert 15 times to thoroughly mix.
13. Wait 5 minutes. DO NOT MIX.
14. Insert tube into chamber, close lid and select SCAN SAMPLE. Record
result in ppm cobalt.
15. Press
OFF button to turn the colorimeter off or press EXIT button to exit
to a previous menu or make another menu selection.
NOTE: For best possible results, a reagent blank should be determined to
account for any contribution to the test result by the reagent system. To
determine the reagent blank, follow the above test procedure to scan a distilled
or deionized water blank. Then follow the above procedure to perform the test
on a distilled or deionized water sample. This test result is the reagent blank.
Subtract the reagent blank from all subsequent test results of unknown samples.
It is necessary to determine the reagent blank only when a new lot number of
reagents is obtained.
COBALT 2/2 COD PLUS TEST PROCEDURES 2/04