APPENDIX A
FILM-BADGE-ACCURACY DATA
A.1.
ACCURACY OF DU PONT FILM PACKET 559 AS A PERSONNEL DOSIMETER
To assist in devising this dosimeter, the Radiological Equipment Section of the U. 8S. National Bureau of Standards carried out a determination of the accuracy to be expected in interpreting dose from photographic densities of Du Pont 502 films exposed to Co®® gamma radiation. Twenty-five readings were made on eachfilm with the following results:
Exposure,
mr
None
30
50
100
300
500
Inaccuracyin dose reading
due to density spread
Density spread
over area of
film sample
0.01
0.02
0.02
0.02 to 0.03
0.02 to 0.03
0.03 to 0.04
Absolute, mr
Percentage
20
30
30
27 to 40
25 to 37
43 to 50
+50
+30
+14 to 20
+4 to 6
#4 to 5
The corresponding percentages of inaccuracy in dose readings from exposures at an effective
x-ray energy of 0.07 Mev were about 3 to 5 per cent better for the 30 and 50 mr exposures and
the same for all higher energies.
RELATIVE SENSITIVITY OF FILMS BEHIND LEAD FILTERS*
Du Pont 502
Mev
Sensitivity
0.04
0.07
0.12
0.17
0.21
Negligible
1.22
0.99
1.02
0.94
1.25
1.00
Du Pont 606
Inaccuracy,
18
1
2
6
%
Sensitivity
high
low
high
low
Negligible
1.23
0.89
0.98
1.07(?)
Accurate
1.00
Inaccuracy,
%
19
12
2
6
high
low
low
high
Accurate
Sensitivity is normalized to the value at 1.25 Mev. Response is assumed to be flat above
1.25 Mev.
,
*0.72 mm of lead.
61
Nadia OY
A.2