RSDetection
User’s Manual
March 2016 S131-200-UM Rev A
Page 56
6.4.1 Sample Calculation
1. Calculate the Exposure Rate at a distance “D” from Co
60
source ‘t” years after
source certification:
49.1uR/h =
E
0.63* 0.982* 0.07475* 1062uR/h =
E
e
*
e
*
365.8
100
1062uR/h =
E
K
*
e
*
D
100
*
E
=
E
uR/h 1062 =
E
1920days)5.26years( = T
)1230.8days3.37years( = t
cm)feet(365.8 12 = D
12
12
/5.26)0.693(3.51-5(265.8)-6.8E-
2
12
d
100)-(D
2
10012
100
1. Sensitivity of the sensor at distance “D” from Co
60
source:
K = [(P+S+A) – (S+A)] / Exposure Rate
k = [-6.124e-12 – -1.403e-12 ] / 202.8e-6 R/h
k = -2.328e-8 amps/R/h
2. Calculate the average sensitivity. In a typical calibration, the following values of k
might be calculated:
3. Calculate the standard deviation σ = 3.6e-11.