3.2 ALTITUDE ABSORPTION MEASUREMENTS
Data on radia.ion versus altitude, over land, are Summarized in Table 3.1.
Scintameter
survey meters were used for the measurements during helicopter missions. A Top Hat radiation
detector and a scintameter were used in the P2V-5 aircraft.
The differences in the absolute values of the readings in the P2V-5 are due to the difference
1090 a
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87 pct of Calibrations
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All Colibrotions Were
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Figure 3.1 Summary
radiation detectors.
of 37 pre- and postflight calibrations of T
yorere
Posene
op H at
in the energy reSponse of the two types of detectors.
po
E ARCHIVESC
The scintameter, TH-3, uses a sodium
iodide phosphor, which is more sensitive to soft gamma radiation. The Top Hat detector uses
a plastic phosphor and has a response that is nearly energy-independent. The response of the
two types of instruments is summarized in Figure B.2. Because fresh fission products have a
25
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TUTOR ee MRNE SSPE EE AELYRE Na Loreen ree ee Te