16
LOCKHART AND PATTERSON
TABLE A2
Calculated 8 Activity from 100 pCi of Radon per m? of
Air Sampled at the Rate of | m?/min for 20 min
.
(min)
Disintegrations
0-20
(p = 0 to 0.190)
40-60
(p = 0.355 to 0.478)
80-100
(po = 0.564 to 0.623)
0
(p = 0.735)
.
_.
Activity Ratio
Final/Initial
Final Activity (61-71)
Initial Activity (t1-11)
Radon Age*
{Countst
Disintegrations
Countst
RaB
RaC
7887
3778
{53.8
315.5
1755
3282
34.2
274.0
Total
11665
469.3
5037
308.2
RaB
RaC
24177
21808
4741S
1821.0
5216
11057
1OL7
923.3
Total
45985
2292.5
16273
1025.0)
RaB
RaC
29976
33035
584.5
2758.4
6449
14403
125.8
1202.7
Total
63011
3342.9
20852
1328.5
RaB
RaC
33221
41689
647.8
3481.0
7136
16562
139.2
1382.9
Total
74910
4128.8
23698
1522.1
Disintegrations
Counts
0.432
0.657
0.354
0.447
0.331
0.397
0.316
0.369
*Conunuously changing age during the 20-min filtration period.
Collected on plass fiber filter of 100% retentivity; counted through LO-mil aluminum absorber.
Taste AS
Age of the Radon/Radon Daughter Mixture
Elapsed
RaC/RaB Atom Ratio (p)
Radon Concentration (pCi/m?)
Time
(min)
Standard
Procedure*
Modified
Procedure?
Expected
Valuef
Standard
Procedure*®
Modified
Proceduret
Expected
Vahuet
0-20
0.052
0.070
0.095
5.42 x 105
3.93 x 105
6.03 x 105
30-50
0.27
0.27
0.34
3.87 x 10
3.66 x 105
6.04 x 105
60-80
0.46
0.45
0.49
3.28 x 105
3.28 x 105
15.93 x 105
90-110
0.51
0.50
0.58
3.07 X 105
3.09 x 105
15.90 « 105
120-140
0.58
0.57
0.61
$3.19 x 105
3.22 x 105
15.89 x 105
150-170
0,60
0.59
0.63
3.06 x 105
3.09 x 105
$5.85 x 105
180-200
0.62
0.61
0.64
2.99 x 105
3.02 x 105
5.84 x 105
260-2806
0.67
0.66
0.70
2.94 x 105
2.96 x 108
6.01 x 105
285-305
0.63
0.62
0.67
2.45 x 105
2.48 x 105
5.81 x 105
*The value ofp is assumed to be constant during the sampling period.
*The value of p is assumed to increase with the age of the radon conglomerate dunng collection.
$Calculations based on modified procedure and taking in accint changes produced by removal of 11.8% of
the aerosol with each sample.
Cee
ange caelRANTETS ee
Comparison of Derived p Values and Radon Concentrations in the Small
Chamber Run (Radon = 6.41 X 10° pCi/m3) Based on a Fixed and a Variable