LaMotte SMART 2 - Manual (Page 112)

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 23 Chromium-TT)
from TESTING MENU.
5. Scroll to and select 23 Chromium-TT from menu.
6. Rinse a tube (0290) with sample water. Fill to 10 mL line with sample.
7. Insert the tube into chamber, close lid and select SCAN BLANK.
8. Remove the tube from colorimeter.
9. Add one *Chromium Spectrophotometric Grade Tablet (3889A).
10. Use Tablet Crusher (0175) to crush tablet.
11. Cap tube.
12. Shake vigorously for 30 seconds.
13. Wait 3 minutes.
14. Insert tube into chamber, close lid and select SCAN SAMPLE. Record
result in ppm chromium.
15. Press
OFF button to turn the colorimeter off or press EXIT button to exit
to a previous menu or make another menu selection.
þ NOTES: 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.
To convert results to ppm chromate (CrO
4
–2 ), multiply by 2.23. To convert
result to ppm sodium chromate (Na
2
CrO
4
) multiply by 3.12.
Chromium-TesTab 1/2 Smart2 TEST PROCEDURES 1.07