LaMotte STH Outfit - Manual (Page 9)

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4. Stand the empty Potash “B” Tube (0246) on the Potassium Reading
Plate (1107), a rectangular piece of white plexiglass with a solid
black line down the middle. Place the tube directly over the black
line.
5. Fill a transfer pipet (0364) with the test sample from the Potash “A”
Tube.
6. Slowly add the test sample to the Potash “B” Tube, allowing it to
run down the side of the tube. Observe the black line down through
the Potash “B” Tube. Continue to add the test sample until the black
line just disappears.
7. Record the value where the level of the liquid meets the scale
printed on the side of the Potash “B” Tube, as pounds per acre
Available Potassium.
8. If the test result is equal to or greater than 400 pounds per acre,
repeat the test on a diluted test sample as follows:
A. Fill a Potash “C” Tube (0247) to the lower mark with the
general soil extract.
B. Add *Universal Extracting Solution (5173) to the upper mark
and mix.
C. Using this diluted extract follow Steps 1 through 7 above.
Multiply the test result by 2 to obtain pounds per acre Available
Potassium.