LaMotte SMART 2 - Manual (Page 91)

PROCEDURE–FREE CHLORINE
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 17 Cl DPD-Liq)
from TESTING MENU.
5. Scroll to and select 17 Cl DPD-Liq 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 5 drops of DPD 1A Free Chlorine Reagent (P-6740).
10. Add 5 drops of *DPD 1B Free Chlorine Reagent (P-6741). Cap and mix.
11. Insert tube into chamber, close lid and select SCAN SAMPLE. Record
result as ppm free chlorine.
PROCEDURE–TOTAL CHLORINE
12. Add 5 drops of *DPD 3 Total Chlorine Reagent (P-6743). Cap and mix.
þ NOTE: For wastewater samples, Standard Methods for the Examination of
Water and Wastewater recommends waiting 2 minutes for full color
development.
13. Insert tube into chamber, close lid and select SCAN SAMPLE. Record
result as ppm total chlorine.
14. Subtract the Free Chlorine reading from the Total Chlorine reading to
determine ppm combined chlorine.
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 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 Chlorine- Liquid DPD 3/3