Humboldt H-4386SM Soil Box - Manual (Page 4)

Soil Box
Attach the "c" binding posts to the end term inals of the box and the “P” binding posts
to the adjacent center terminals. (see fig. 1)
fig. 1
Balance and read in the usual way. Apply the correct multiplying factor, if any,
for the box you are using. To obtain the resistivity of a sample of soil or water,
the box should be filled even with the top, with no voids.
2-Pin Method
To measure the resistance between two pins or anodes, connect “C1” and “P1” and
“C2” and “P2” to the two pins or anodes, using separate leads. (see fig. 2)
fig. 2
Balance and read in the usual way. Note that this reading includes the resistance
of the two pins or anodes to the soil, the soil resistance between them, and the
resistance of any cables from the connections to the anode or rod.