LaMotte SMART3 Colorimeter - Manual (Page 136)

6. Remove fl ask from heat. Cool sample under running water. This is the digested
sample.
7. Pour digested sample into clean graduated cylinder (0418). Dilute to the 50 mL
line with Deionized Water (5115).
8. Press and hold until colorimeter turns on.
9. Press ENTER to select TESTING MENU.
10. Select ALL TESTS or another sequence containing 021 Chromium) from
TESTING MENU.
11. Scroll to and select 021 Chromium from menu.
12. Rinse a clean tube (0290) with sample water. Fill to 10 mL line with sample
water.
13. Insert tube into chamber, close lid and select SCAN BLANK.
14. Remove tube from colorimeter. Use 0.1 g spoon (0699) to add one level
measure of *Chromium Reagent Powder (V-6276). Cap and shake for one
minute. Wait 3 minutes.
15. During the waiting period, fold a piece of fi lter paper in half, then in half again to
form a cone. Push corners together to open end, and insert into funnel (0459).
16. Filter sample into a clean tube (0290). Cap and mix. Insert tube of fi ltered
sample into chamber, close lid and select SCAN SAMPLE. Record result.
17. Press to turn colorimeter off or press
EXIT
to exit to a previous menu or
make another menu selection.
TRIVALENT CHROMIUM PROCEDURE
Subtract hexavalent chromium from total chromium. Record as ppm trivalent
chromium.
Trivalent Chromium = Total Chromium – Hexavalent Chromium
CHROMIUM, Hexavalent, Trivalent, Total SMART3 Test Procedures 11.10
Test P
rocedures