sion of better than two percent, including drift effects, over a three-week period.
The
completed detector head, including ion chamber and electronics, was encapsulated in
Hysol 6020 casting resin. A typical calibration curve for these detectors is given in
Figure 2.2.
2.2.2 Residual Instrument System Recorder. The two-channel recorder used with
this system consisted of an Esterline~Angus-chart drive to supply the time base and
19°
io *
be
= 103
he
©
°
a
»
he
07
a
”
°
a
«
ud
o
io
-—
g
= 7 February
oO
o
O
A: 2! February
\
1o7!
= 8 Febr
ebruary
1072
o~
107!
i
10
102
Frequency, pulse/min
Figure 2.2 Graph showing a typical calibration curve for
the Conrad detectors. These detectors were calibrated
with the 200-curie Co® source and the 250-kv X-ray generator.
two electric styluses writing on Teledeltos paper charts. The output from the detector
head was fed through an amplifier directly to Stylus No. 1, which produced a mark for
each detector-output pulse. In addition, the detector output was fed to a scale-of-11
counter, thence tu Stylus No. 2. Thus, Stylus No. 2 produced one mark for each 11 output pulses from the detector. In this manner, a chart speed slow enough for the required
five-day operating period could be used while maintaing resolution of the fastest anticipated pulse~repetition rate. In operation, the record from Stylus No. 1 was used until
21