LaMotte STH Series - Manual (Page 15)

Procedure:
1. Use a transfer pipet (0364) to transfer five drops of the
general soil extract to a flat-bottomed glass turbidity vial
(0242).
2. Add one drop of *Calcium Test Solution (5108PS). Swirl
gently to mix.
3. Match the milky turbidity of the test sample against the
turbidity standards on the Replaceable Calcium Chart
(1303). Lay the chart flat under natural light and hold the
turbidity vial one-half inch above the black strip in the
middle of the chart. View the black strip down through the
turbid sample and compare the resulting shade of gray with
the six standard shades. The test result is read in parts per
million replaceable calcium.
4. If the test sample turbidity corresponds to or exceeds the
lightest standard (2800 ppm), repeat the test on a diluted
sample. Transfer one drop of the general extract to a clean
turbidity vial and add four drops of demineralized water. Then
follow Steps 2 and 3 as above. Multiply the test result by 5 to
obtain parts per million replaceable calcium.
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