LaMotte SMART3 Colorimeter - Manual (Page 132)

PROCEDURE
1. Press and hold until colorimeter turns on.
2. Press ENTER to select TESTING MENU.
3. Select ALL TESTS (or another sequence containing 021 Chromium) from
TESTING MENU.
4. Scroll to and select 021 Chromium from menu.
5. Rinse a clean tube (0290) with sample water. Fill to the 10 mL line with sample.
6. Insert tube into chamber, close lid and select SCAN BLANK.
7. Remove tube from colorimeter. Use the 0.1g spoon (0699) to add one measure
of *Chromium Reagent Powder (V-6276). Cap and shake until powder
dissolves. Wait 3 minutes for full color development.
8. During waiting period, fold a piece of fi lter paper (0465) in half then half again
to form a cone. Push corners together to open end, and insert into funnel
(0459).
9. At the end of 3 minute waiting period, fi lter sample into a clean tube. Mix. Insert
tube into chamber, close lid and select SCAN SAMPLE. Record result.
10. Press to turn colorimeter off or press
EXIT
to exit to a previous menu or
make another menu selection.
NOTES: To convert result 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.
Highly buffered waters may give poor results and require a more careful pH
adjustment. Before adding *Chromium Reagent Powder, adjust pH of sample to
pH 3–4.
CHROMIUM, Hexavalent SMART3 Test Procedures 11.10
Test P
rocedures