LaMotte SMART 3 Electronic Soil Lab - Manual (Page 58)

58 SMART3 Soil 1.11
PROCEDURE
Press and hold 1. until colorimeter turns on.
Press 2. ENTER to select TESTING MENU.
Scroll to and select 3. ALL TESTS (or another sequence containing 005
Ammonia-N HR) from TESTING MENU.
Scroll to and select
4. 005 Ammonia-N HR from menu.
Use the 1 mL pipet (0354) to transfer 2 mL of soil extract into a clean tube 5.
(0290). Dilute to the 10 mL line with deionized water. Mix and neutralize
according to the procedure on page 56.
Insert tube into chamber, close lid and select SCAN BLANK. (See Note)
6.
Remove tube from colorimeter. Add 12 drops of Ammonia Nitrogen Reagent 7.
#1 (V-4797). Cap and mix. Wait 1 minute.
Use the 1.0 mL pipet (0354) to add 1.0 mL of *Ammonia Nitrogen Reagent
8.
#2 (V-4798). Cap and mix. Allow 5 minutes for maximum color development.
At end of the 5 minute waiting period, immediately mix, insert tube into
9.
chamber, close lid and select SCAN SAMPLE. Multiply the result by 50 to
determine the ammonia-nitrogen concentration in lb/acre.
Press
10. to turn the colorimeter off or press the
EXIT
exit to a previous
menu or make another menu selection.
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.
AMMONIA NITROGEN CONCENTRATION CHART
POUNDS PER ACRE RANGE
0-24 lb/acre Low
25-68 lb/acre Medium
Over 71 lb/acre High
Test P
rocedures