Hanna Instruments HI 38083 User Manual

Page 2

The chemicals contained in this kit may be hazardous if
improperly handled. Read the relevant Health and Safety

Data Sheet before performing this test.

HEALTH AND SAFETY

REFERENCES

P. Sequi, Chimica del suolo, Patron Editore, Ed. 1991

• To obtain the soil extract mea-

sure in the small (14 mL)
test tube 0.5 mL of the pre-
pared soil and add with the
3 mL pipette the saturated
calcium sulfate extractant so-
lution up to the 11 mL mark.

• Replace the cap and

shake vigorously by
striking the tube

against the palm of
your hand, to com-
pletely suspend the
soil. Shake the tube
three times for 1
minute at 10 minute

intervals.

• Place the cap on one of the small (20

mL) calibrated vessels and insert the
funnel into the cap hole.

• Fold a filter paper disc twice as shown in the figure.

• Separate one side from

the other three to form a
cone.

• Place the folded filter disc

into the funnel and filter
the sample by pouring the
soil extract into the cone.
The extracted sample in

the beaker is now ready
for analysis.

DETERMINATION OF GYPSUM REQUIREMENT
• Take the syringe and push the

plunger completely down into the

syringe. Insert tip into sample and

pull the plunger out until the lower

edge of the seal is on the 0.0 mL

mark of the syringe.

x 4

x 1

• Insert the syringe into

the other small plastic

vessel and push the

plunger out until the

lower edge of the seal

is on the 1.0 mL mark.
Add to the vessel dem-
ineralized water from

the Demineralizer Bottle
up to the 10 mL mark.

• Add 4 drops of Buffer Solution 10.2±0.2, 1 drop of

Calmagite Indicator and swirl to mix.

• Using the 1 mL plastic pipette, add drops of HI 38083C-0

EDTA Solution, swirling after each drop, while keeping
an accurate count of the number of drops being added
to the solution.

• Continue adding EDTA Solution until the solution in the

vessel changes from red-violet to pure blue. If necessary
refill the pipette with EDTA Solution, while keeping
count of the drops being added. Record the number of
drops needed to obtain the final color change (from
wine red to pure blue).

• Calculate the Gypsum Requirement as follows:

GR (meq/100 grams of soil) = 56 - drops added
GR (ton/acre)

= (meq/100 g) x 1.7

GR (metric ton/ha)

= (meq/100 g) x 3.81

Note: if more than 56 drops need to be added, there is no

Gypsum Requirement.

• Calculate the Estimated Exchangeable Sodium as fol-

lows:

EES (meq/100 grams of soil) = 0.99 x GR (meq/100 g) + 0.96

0.5 mL

of soil

11 mL

10 mL