li
monitoring water was constructed by the HASL, NYOO.
This in-
stallation differed from that used during Operation Troll” in
that the probe was mounted in a cylindrical, rubber-lined tank, 4
feet in diameter and 6 feet long (Fig. 1).
~
Water from the sur-
face of the sea was passed through the tank at the rate of
about 30 gallons per minute.
The sensing probe contained a plastic phosphor three inches
in diameter and thirty inches long, a photomultiplier tube, and
.
a battery-operated preamplifier.
hes
:
The probe unit was connected
to a control box inside the ship by two coaxial lines,
voltage line and the signal line.
the high
The control box contained am
AC-operated high voltage supply and a DC amplifier with output
scales of 5,
50,
500, and 5,000 microroentgens.
The signal from
e
+ ttletatiana veetadnese on
the control box was fed into an Esterline Angus recorder which
So
was operated at a chart speed of three inches per hour.
The
scintillation unit was operated throughout the duration of the
trip.
METHODS OF ANALYSES
Preliminary analyses of the plankton and surface water were
carried out on board the WALTON.
Further determinations were
made at the EMBL and at the Applied Fisheries Laboratory.
Counting Equipment:
Samples were prepared on 14-inch
Stainless steel plates and counted with a 2 inch Anton tube in
" Harley,
John H.,
March 1956,
Editor,
Operation Troll,
NY0-4656,
Pon
wed
*
ue
'