EXAMPLE PROBLEM 1.

Given:

R1 = 100 cGyph and **n **= 0.8

Find:

Rt at H + 7 hours

Answer:

20 cGyph

SOLUTION: Using Figure 6-6, align the hairline with 7-hour tickmark of the 0.8 time scale and equal

values of the left and right reference lines. Mark a point on the index scale where the hairline intersects

it. Then pivot the hairline about this point to the 100 cGyph tickmark on the R1 scale. Read the dose

rate at H + 7 as 20 cGyph at the point of intersection of the hairline with Rt scale.

EXAMPLE PROBLEM 2.

Given:

R1 = 2,000 cGyph, Rt = 45 cGyph, and **n **= 2.0

Find:

The time when the dose rate will be reduced to 45 cGyph

Answer: H + 6.75

SOLUTION: Using Figure 6-7, align the hairline with 45 cGyph on the Rt scale and 2,000 cGyph on

the R1 scale. At the intersection of the hairline with the index scale, pivot and align equal values on the

left and right reference lines. Read 6.75 hours at the point of intersection of the hairline with the 2.0

time scale.