LaMotte SMART 2 - Manual (Page 234)

PROCEDURE
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 81 Potassium)
from TESTING MENU.
5. Scroll to and select 81 Potassium from menu.
6. Rinse a clean tube (0290) with sample water. Fill to the 10 mL line with
sample.
7. Insert tube into chamber, close lid and select SCAN BLANK.
8. Remove tube from colorimeter. Add 4 drops of *Sodium Hydroxide, 1.0N
(4004WT). Cap and mix.
9. Use the 0.05 g spoon (0696) to add one measure of *Tetraphenylboron
Powder (6364). Cap and shake vigorously until all of the powder has
dissolved. Wait 5 minutes.
10. At end of 5 minute waiting period, mix tube again to suspend any settled
precipitate. Insert tube into chamber, close lid and select SCAN SAMPLE.
Record result.
11. Press
OFF button to turn colorimeter off or press EXIT button to exit to a
previous menu or make another menu selection.
þ NOTES: 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 are obtained.
For the most accurate results, the sample and reagents should be at 25±4°C.
Potassium 2/2 Smart2 TEST PROCEDURES 2.04