SOLUTION:

Align the hairline with the 7-hour tick mark on the Soil

Type III scale (Figure 5-8) and equal values of the left

and right reference lines.

Pivot the hairline about its

point of intersection with the index scale to the 300 cGyph

point on the R1 scale. Read the dose rate as 50 cGyph at

the point of intersection with the Rt scale.

ANSWER:

50 cGyph.

GIVEN:

R1 = 280 cGyph.

FIND :

Time when Rt = 90 cGyph.

SOLUTION:

Since the soil type is not indicated, Soil Type II (Figure

5-7) must be used for this calculation. Connect 280 cGyph

on the R1 scale and 90 cGyph on the Rt scale. Read time as

H + 15 hours on the Soil Type II (index) scale.

ANSWER:

H + 15 hours.

GIVEN:

R1 = 200 cGyph.

FIND:

Time when Rt = 70 cGyph in Soil Type IV.

SOLUTION:

Connect 200 cGyph on the R1 scale and 70 cGyph on the

Rt

scale.

Holding the hairline firmly at its point

of

intersection with the index scale, align equal values

on

the left and right reference lines.

Read time as H +

10

hours at the point of intersection with the Soil Type

IV

scale (Figure 5-9).

ANSWER:

H + 10 hours.