LaMotte SMART 2 - Manual (Page 203)

CARBOHYDRAZIDE 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 14 c-hydrazide
from TESTING MENU.
5. Scroll to and select 14 c-hydrazide 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. Add 3 drops of *DEHA Reagent #1 (4791). Swirl to mix.
10. Add 3 drops of *DEHA Reagent #2 (4792). Swirl to mix.
11. Add 3 drops of *DEHA Reagent #3 (4793). Invert 3 times to mix.
12. Insert the tube into chamber. Close lid.
13. Wait 15 minutes. Do not open the lid during the waiting time. The
reaction is photosensitive.
14. Remove tube from chamber. Invert 2 times to mix.
15. Immediately insert tube into chamber, close lid and select SCAN SAMPLE.
Read within 30 seconds. Record result in ppm carbohydrazide.
16. Press
OFF button to turn the colorimeter off or press EXIT button to exit
to a previous menu or make another menu selection.
þ 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.
Smart2 TEST PROCEDURES 2.04 Oxygen Scavengers 3/6