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1.
1.1
INTRODUCTION
Tritium activities measured in samples of atmospheric water
are related to the equivalent weight of atmospheric air from which
the water was extracted.
The concentration of tritium per gram of air
is calculated from a number of collections of whole air made from
various levels within the atmosphere to altitudes of 90,000 feet mean
sea level.
Air collections were made by aircraft and by balloon-borne
apparatus under the sponsorship and direction of AFOAT-1.
Collection
of these samples, analytical procedures employed, methods of calculation
and the errors associated with the final values, are discussed briefly
in the ensuing paragraphs.
2.
2.1
COLLECTION, SAMPLING AND ANALYSIS
Collection
For sampling at altitudes of 50,000 feet and higher, the collection
equipment is carried aloft on a constant altitude lift balloon.
The
collection equipment consists of a centrifugal collection blower, a
deuterium spike dispenser capable of edding an accurately lnown veight
of Ds0 to the contents of the collection bag at the time of sarpling,
éid a 30,000 cubic foot polyeth,;lene collection bag.
The Do0 is kept at a constant tesperature of 95°F and about 2 to 5
grams of vapor dispensed unifornly with tine at a point just behind the
centrifugal blower during collection of the air sauple.
The dispenser is
weighed before end after each collection to determine the nusber of atoms
of deuterium added as the tracer.
Both bag and dispenser are effectively