Ludlum Measurements 319110, Руководство пользователя

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Model 44-110-4 Windowless Gas Flow Proportional Detector
page 1
1. GENERAL
The Model 44-110-4 is a windowless gas flow
proportional sample counter capable of
holding up to a 5.1 cm (2 in.) diameter filter
or
planchet. High Voltage (HV) is
continuously applied to the detector. The
sample drawer is locked in the closed position
by rotation of the sample drawer lever
mounted on the side of the instrument.
If simultaneous alpha-beta discrimination is
desired, the counting instrument must have
separate power supplies or threshold controls
for each channel. The Ludlum Model 3030
Scaler or Model 2360 instruments provide the
necessary circuitry for simultaneous alpha-
beta discrimination. Otherwise, a single-
channel instrument, such as the Model 2200,
may be adjusted to count alpha, beta, or both.
2. SPECIFICATIONS
DETECTOR OPERATING VOLTAGE:
typically 1700-1900 Vdc
GAS FLOW: typically 0.1 L/min, detector
equipped with 3.2 mm (0.125 in.) hose
connection and two-position switch flow
valve
EFFICIENCY (4π):
3% for
3
H; 21% for
14
C; 36% for
63
Ni; 42% for
239
Pu
COUNTER THRESHOLD SETTINGS:
typically 2-5 mV
SAMPLE SLIDE AND HOLDER :
anodized aluminum tray with 2.5 cm (1.0
in.) diameter sample ring to allow for 2.5 or
5.1 cm (1.0 or 2.0 in. (Dia x L) samples
CONSTRUCTION : aluminum housing
TEMPERATURE: -20 to 50 °C (-4 to 122
°F)
SIZE: 15.2 x 11.4 x 23.6 cm (6 x 4.5 x 9.3
in.) (H x W x L)
WEIGHT: 1.5 kg (3.3 lb)
3. OPERATING PROCEDURES
Connect the Model 44-110-4 to an
appropriate counting gas by connecting
tubing from a gas bottle regulator or
adjustable flow meter to the hose barb on the
toggle valve. Regulate the flow to
approximately 0.1 L/min. The hose barb on
the back of the housing is exhaust gas. The
exhaust can be left unconnected or it can be
connected to tubing to route the exhaust to
another location.
Connect the detector to the counting
instrument. The coax cable with "C"
connectors carries both the signal and HV.
High Voltage (HV) is continuously applied
to the detector.
To check a radioactive sample, place sample,
facing up, in the appropriate size cavity in
the sample holder for the 2.5 or 5.1 cm (1 or
2 in.) filters. Do not allow the sample to
extend above the top of the sample slide.
Push the sample drawer in completely, then
rotate the sample drawer lever to the locked
position, securing sample drawer in the
closed position.
Open toggle valve by moving lever on top of
valve to the open position. Allow chamber
to purge for approximately 30 seconds