LaMotte SMART Spectro Spectrophotometer - Manual (Page 199)

PROCEDURE
Use universal sample holder.
NOTE: Place Dispenser Cap (0692) on *Mixed Acid Reagent (V-6278). Save this
cap for refi ll reagents.
1. Press and hold ON button until spectrophotometer turns on.
2. Scroll to and select PROGRAMMED TESTS.
3. Scroll to and select ALL TESTS (or another sequence containing
67 Nitrite-N LR) from TESTING MENU.
4. Scroll to and select 67 Nitrite-N LR 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.
7. Remove tube from Spectro and pour off 5 mL into a graduated cylinder or
similar. Discard the remaining sample.
8. Pour the 5 mL sample from the graduated cylinder into the colorimeter tube.
Use graduated cylinder or similar to measure 5 mL of *Mixed Acid Reagent (V-
6278) and add to tube. Cap and mix.
9. Use the 0.1 g spoon (0699) to add two measures of *Color Developing
Reagent (V-6281). Cap and mix by gently inverting for 1 minute. Wait 5 minutes
for maximum color development.
10. At the end of the 5 minute waiting period, mix, insert tube into chamber, close
lid and select SCAN SAMPLE. Record result.
11. Press OFF button to turn spectrophotometer off or press EXIT button to exit to
a previous menu or make another menu selection.
NOTE: To convert nitrite-nitrogen (NO
2
–N) results to ppm nitrite (NO
2
), multiply
results by 3.3.
NITRITE-NITROGEN, Low Range SMART Spectro Test Procedures 2.11
Test P
rocedures