LaMotte SMART 3 Electronic Soil Lab - Manual (Page 68)

68 SMART3 Soil 1.11
PROCEDURE
Press and hold 1. until colorimeter turns on.
Press 2. ENTER to select TESTING MENU.
Select 3. ALL TESTS (or another sequence containing 051 Iron Bipyridyl)
from TESTING MENU.
Scroll to and select
4. 051 Iron Bipyridyl from menu.
Fill a clean tube (0290) to the 10 mL line with the soil extract then neutralize 5.
according to the procedure on page 50.
Insert tube into chamber, close lid and select SCAN BLANK.
6.
Remove tube from colorimeter. Use the 0.5 mL pipet (0353) to add one 7.
measure of *Iron Reagent #1 (V-4450). Cap and mix.
Use the 0.1 g spoon (0699) to add 0.1 g of *Iron Reagent #2 Powder
8.
(V-4451). Cap and shake vigorously for 30 seconds. Wait three minutes for
maximum color development.
At the end of 3 minute waiting period, do not mix. Insert tube into chamber,
9.
close lid and select SCAN SAMPLE. Multiply the result by 5 to determine the
iron concentration in ppm.
Press
10. to turn colorimeter off or press
EXIT
to exit to a previous menu
or make another menu selection.
NOTE: 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 is obtained.
IRON CONCENTRATION CHART
PARTS PER MILLION RANGE
0.0-1.3 ppm Very Low
1.4-3.0 ppm Low
3.0-5.0 ppm Medium
5.0-10.0 ppm Medium High
Above 10.0-25.0 ppm High
Test P
rocedures