set
7
-
oe
-
Diurnal Variation. Shortly after their inataliation, te
_7. ane tI SAMPLES
film analyses from the Yorld Wide Sampling Network.“
Automatic Monitoring
Instruments Down Time.
Monitoring sta-
toms
Fortunately, mch of the down tine occurred
a between events so that usefil data was lost only at the following
stations during the stated fallout periods: BRAVO- Nwajalein,
Wake, Ponape and Iwo Jima; ROMEO- Kusaie, Ujelang, Yap, and lwo
~» dimmg KOON Yap, and Iwo Jinn; UNTO’, YANKEE, AND NECTAR~ Joonaton,
The presented cumulative radistion values are therefore, in general
tnderestimations. ‘he values are cased on the recorded data only
which account, on the average, for 55% of the duration of CASTILE.
olb-
.
-
.
.
to.
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t
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oS
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ut
ayer
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vate
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@ wt walauromaric eonrtoe!
ta herntest
awe,
ea
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a,
.
:
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vee
§
perpen,
.
att
8 vee
March 1 to Mey 20.
oe 3.
4
<
tions were out of servile for an average of 15% of the tice from
s
T
.
In each case,
the gummed file displayed an increase in activity corresponding
to the monitor data. Thus, the monitor date was qualitatively
wabstantiated. &n example of the comparison of the gummed fila
meenits with automatic monitor values ig shown in Figure 29.
C.
SP UP
as
»
+
o$ ahs
BC
ison with Gumed Film. In those instances of suspected
failout rere diurnal variation rendered monitor data of queattonable validity, the data were compared with the apprypriate gusmed
—
ni
it
arsannaet
The diurnal variation was consistently so high ct Guam ttat none
?
$
.
the 1800 Z value was used for plotting time graphs. Similarly,
at several stations only the 1300 Z walues were used in computing
cumilstive radiation,
of those data, 21l of which are low level, are considered valid.
.
“ou of
liable measure of low intensity radiation. In several instances
of Light fallout, (Ponape-ROMEO, Truk-BRAVO, Truk-YANCEB) only
‘
’
ssn tee = Be
SPae ae oe ae em ee OP a ne ee ee ceatendieaiedianee eK
ne
s
.
1
4
that the late night instrument reeding was in most cases 2 re-
1904
wee
Dor bend
A review of the data and the ingtruments’ behaviour hae indicated
ht
yr:
aot
>
atolls in the area.
rebeg,
ben
possible that significant fallout my have been detacted at other
0
¢
peyreerh A COR pre Sey (oe tee
.
difficult and on one occasion, fallout of low intensity was un*noticed wien it cccurred. A later, careful analysis of the data
revealed that 0.15 ar/hr occurred at Ponape after ROMEO. Had this
been known, a CPARLIE survey would hare heen executed ard it is
‘
‘
sae
-
-
Interpretation of radiation intensities less than 0.1 erAir was
1
AT ARNG '
:
oo
a.
:
{
?
*
j
i
1
weete
ewoem nenee
ation apparently due to temperature change, humidity, or both.
The variation was as great as an order ofmagnitude in some inetrumenta. For this reaeon, ths practical lower Limit of deec-
tion was about 0.1 mr/hr slthcugh the design linit wag 0.001 ax/hr.
4,
ty
TPT INPIEATED AY autowATIC wometge
aC operated automatic monitors displayed a rmgular dhimal vari-
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COMPANATIVE FALLOUT activity
8
1. Automatic Monitoring Stations
A.
pl.
tri
|'
.
FACTORS RELATING TC DATA INTERPRETATION
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