LaMotte DCL-20 Colorimeter - Manual (Page 8)

pH
PROCEDURE
1. Use the 10 g Soil Measure (1164) to add one level measure of the soil sample to a 50 mL beaker (0944). Use the
graduated cylinder (0416) to add 10 mL of deionized water. Stir thoroughly.
2. Let stand for at least 30 minutes, stirring two or three times.
3. Read pH on pH meter. Stir mixture just prior to making the pH reading.
LIME RE QUIRE MENT - WOOD RUFF METHOD
PROCEDURE
1. Use the 10 g Soil Measure (1164) to add one level measure of the soil sample to a 50 mL beaker (0944). Use the
graduated cylinder (0416) to add 10 mL of deionized water. Stir thoroughly.
2. Let stand for at least 15 minutes.
3. Add 20 mL of Woodruff Buffer Solution (5272). Mix well, and let stand for at least 20 minutes, stirring two or three
times.
4. Read on pH meter. Stir mixture just prior to making reading.
5. Each 0.1 pH unit drop from pH 7.0 indicates a lime requirement equivalent to 1000 lbs calcium carbonate (CaCO
3
).
8
1985-01 • 10/01