LaMotte MORGAN SOIL pH TEST KIT ST-M - Manual (Page 3)

NOTES & PRE CAU TIONS
1.
Do not conduct tests in a closed stable in the presence of fumes from
decomposing manure, or in a laboratory where ammonia or acid
fumes are present.
2. Compare colors in diffused daylight. Comparison of colors in direct
sunlight or artificial light may result in incorrect readings.
3. Wash spot plate with Distilled Water (5115PT) prior to testing,
particularly when alkaline soils are to be tested. A change of color as
liquid passes down the channel indicates that impurities on the plate
have interfered in the test reaction.
4. Avoid contact between soil sample and hands, fertilizers, sprays, etc.
See the LaMotte Soil Handbook for a detailed discussion of collection,
preparation, and handling of soil samples.
5. Some soils may be more acid than pH 3.8; others may be more
alkaline than pH 8.4. LaMotte Company furnishes narrow range
indicators and color charts to measure these extreme ranges:
Bromphenol Blue, pH 3.0 - 4.6; Thymol Blue, pH 8.0 - 9.6.