in place in less than 1 second.
trol room.
Putting the source in position was done remotely from the con-
The source had been calibrated by the use of a Victoreen R~meter, which was cali-
brated at the National Bureau of Standards to an accuracy of +3 percent. The source calibration
curve is shown in Figure 2.11. The configuration of the source room was such that only one
NBSfilm holder could be exposed at one time. The Kodak 548-0 film packets were placed inside
CE
L
a
]
fo}
{itt
ryy]
a”
DOSE RATE , r/hr
TUT
{1 it
F
1 |
10
2
4
6
8
FREQUENCY, |O7 cps
iO
12
i@
,
Figure 2.9 Calibration curve for Kaiser dose-rate instrument, 750-yard station.
their NBS holders at 5¥, inches from the window of the shield and exposed from 200 to 1,400
seconds, giving the film a total dose from a minimum of 1,000 r to a maximum of 7,000 r.
The Dupont 553 film packets inside their NBS holders were placed at distances of 5Y, to 112
inches from the shielded window and exposed from 40 to 400 seconds to give the film exposures
within the range of 1 to 2,000 r. The calibration curves are shown in Figure 2.12.
All of the Kodak 548-0 film packs were calibrated inside a steel pipe holder, The Dupont
553 film packs were calibrated both inside and outside the pipe holders.
The 7-curie source was used to calibrate the film for small total doses. The film packets
inside their NBS holders were exposed to a total dose from a minimum of 0,1 r to a maximum
21