LaMotte SMART 2 Electronic Soil Lab - Manual (Page 80)

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 89 Sulfate-HR)
from TESTING MENU.
5. Scroll to and select 89 Sulfate-HR from menu.
6. Use the 1 mL pipet (0354) to add 1 mL of *Sulfate Extracting Solution
(6363) to the test tube (0701) then add deionized water to the 15 mL line.
7. Add 3 one gram measures of soil using the 1 g spoon (0697). Cap vial and
shake for five minutes.
8. Filter and collect all of the soil filtrate using the funnel (0459) and filter
paper (0463). If the filtrate is not clear, filter a second time.
9. Fill a clean tube (0290) to the 10 mL line with the soil extract.
10. Insert tube into chamber, close lid and select SCAN BLANK..
11. Remove tube from colorimeter. Use the 0.1 g spoon (0699) to add one
measure of *Sulfate Reagent (V-6277). Cap and shake until powder
dissolves. A white precipitate will develop if sulfates are present. Wait 5
minutes.
12. Mix tube again. Insert tube into chamber, close lid and select SCAN
SAMPLE . Multiply the result by 1.65 to determine the sulfur
concentration in ppm.
13. Press OFF button to turn colorimeter off or press EXIT button to exit to a
previous menu or make another menu selection.
NOTES:
l If the sulfate concentration of the test sample is greater than 100 ppm, it is
recommended that a dilution be made with deionized water and the results
multiplied by the dilution factor.
l A white film is deposited on the inside of test tubes as a result of the
sulfate test. Thoroughly clean and rinse test tubes after each test.
l For the most accurate results, samples and reactions should be at 25±4°C.
n
SULFUR CONCENTRATION CHART
PARTS PER MILLION RANGE
0-16 ppm Low
17-30 ppm Medium Low
31-50 ppm Medium
52-75 ppm High
80 SMART2 SOIL MANUAL 1.07