LaMotte SMART3 Colorimeter - Manual (Page 83)

1. Press and hold until colorimeter turns on.
2. Press ENTER to select TESTING MENU.
3. Select ALL TESTS (or another sequence containing 004 Ammonia-N LRS)
from TESTING MENU.
4. Scroll to and select 004 Ammonia-N LRS 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. Use the 1.0 mL plastic pipet (0354) to add 2.0
mL of *Salicylate Ammonia #1 (3978). Cap and mix.
8. Use the 0.15 g spoon (0727) to add two measures of *Salicylate #2 Reagent
(7457). Cap and mix until dissolved. Wait 1 minute.
9. At end of 1 minute waiting period use 0.1 g spoon (0699) to add two measures
of *Salicylate #3 Reagent Powder (7458). Cap and shake vigorously for at
least 30 seconds and all solid has dissolved. Wait 20 minutes for maximum
color development.
10. At the end of the 20 minute waiting period, immediately mix and insert tube into
chamber, close lid and select SCAN SAMPLE. Record result.
11. Press to turn colorimeter off or press
EXIT
to 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, Low Range
Test P
rocedures