LaMotte SMART3 Colorimeter - Manual (Page 85)

PROCEDURE
1. Press and hold until colorimeter turns on.
2. Press ENTER to select TESTING MENU.
3. Scroll to and select ALL TESTS (or another sequence containing 005
Ammonia-N HR) from TESTING MENU.
4. Scroll to and select 005 Ammonia-N HR 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. (See Note)
7. Remove tube from colorimeter. Add 8 drops of Ammonia Nitrogen Reagent #1
(V-4797). Cap and mix. Wait 1 minute.
8. Use the 1.0 mL pipet (0354) to add 1.0 mL of *Ammonia Nitrogen Reagent #2
(V-4798). Cap and mix. Allow 5 minutes for maximum color development.
9. At end of the 5 minute waiting period, immediately mix, insert tube into
chamber, close lid and select SCAN SAMPLE. Record result.
10. Press to turn the colorimeter off or press the
EXIT
exit to a previous
menu or make another menu selection.
CALCULATIONS:
To express results as Unionized Ammonia (NH
3
):
ppm Unionized Ammonia (NH
3
) =
ppm Ammonia-Nitrogen (NH
3
–N) x 1.2
To express results as Ionized Ammonia (NH
4
):
ppm Ionized Ammonia (NH
4
+ ) =
ppm Ammonia-Nitrogen (NH
3
–N) x 1.3
To determine the percentages of Unionized and Ionized Ammonia-Nitrogen, consult
the Appendix.
NOTE: It is strongly suggested that a reagent blank 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.
SMART3 Test Procedures 11.10 AMMONIA NITROGEN, High Range
Test P
rocedures