Model 239-1F Floor Monitor
December
2010
1. GENERAL
The Model 239-1F Floor Monitor is a gas
proportional floor monitor detector mounted on
a roll-around cart. The instrument features a
flow system, quick-connects, a gas bottle
mount, and a means to adjust the height of the
detector from the floor for optimum
performance. A nuclear counting gas bottle,
gas regulator, and a survey instrument are
required for the operation of the floor monitor.
The
survey
instrument should be capable
of supplying up to 2500 volts to the detector.
The floor monitor utilizes quick-connect
fittings on the supply side of the input flow
meter and the external outlet line of the output
flow meter for flow operation. An input line to
the flow meter with quick-connect is attached
from the portable gas bottle mounted on the
frame of the cart.
2. SPECIFICATIONS
•
DETECTOR
SIZE
: 2 x 16 x 46.5
cm (0.8 x 6.3 x 18.3 inch) (H x W x L)
•
DETECTOR
ACTIVE
AREA
: 584
cm
2
•
ADJUSTABLE
HEIGHT
: Detector
adjusts from 0 inches to 1
½
inches from floor
•
WINDOW
MATERIAL
: (a) 0.4 or
0.8 mg/cm
2
(one or two layers metalized
mylar) alpha, beta/gamma; (b) 3.9 mg/cm
2
(one layer metalized mylar, one layer 3.5
mg/cm
2
mylar) beta/gamma; (c) 7.9 mg/cm
2
(one layer metalized mylar, one layer 7.5
mg/cm
2
mylar) gamma
•
EFFICIENCY (4
π
):
17%-
239
Pu;
25%-
90
Sr/
90
Y; gamma <1%. Efficiencies are
expressed in 4pi geometry and calculated with
a probe using the 0.8 mg/cm
2
Mylar window
at a fixed height of 3/16 inches distance from
the floor
•
COUNTER
: Any instrument suitable
for use with proportional detectors and
capable of 2500V operation.
•
CONNECTOR
: Series "C" type
•
QUICK-CONNECTS
: Swagelock
(brand) 1/8 mpt to 1/4 O. D. tubing.
•
GAS
CONSUMPTION
:
approximately 35 cc/min.
•
FLOW
METERS
: Both IN and OUT
0-100 cc/min.
•
FLOW RATE
: 35 cc/min after
purging
•
MAXIMUM GAS CYLINDER
SIZE
: Size is 9 inch diameter x 26 inches;
0.60 cu. ft. capacity
•
WIRE
: 0.001 inches diameter
platinum (8 % Tungsten alloy)
•
STANDOFFS
: Concord 1102-23 -
0019
●
CART:
∗
Handle Height: 3.5 ft.
∗
Length: 66.04cm (26 inch),
including wheels, but excluding
handle.
∗
Width: 46.36 cm (18.25 inch)
∗
Wheel Size: Rear 8 inches, front 3
inches swivel.
∗
Finish: Computer Beige powder
coat paint.
•
WEIGHT:
20 lbs. without gas cylinder
and counting instrument.
3
See instrument manual for specifications and instructions for the counting instrument.
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