Fluke Biomedical 945A - Manual (Page 10)

Specifications, Ion Chamber Detector
Detector Type Ionization chamber
Detector Volume Approximately 1000 cc
Detector Constant
Approximately 8 x 10-11 A/R/h
Detector Capacitance 30 Picofarads nominal
Inner Chamber Gas Dry nitrogen @ atmospheric pressure
Radiation Detected Gamma and X-Ray
Detectable Range
1 x 10-1 to 1 x 107 mR/h
Energy Dependence ± 10% from 60 keV to 3 MeV (Refer to Figure 1-1)
Accuracy ± 15% of true dose for Cs-137
Power Requirement Approximately 500 VDC; high voltage level verified
through auto-check routine
Check Source Electronic check source actuated from UDR front panel
Dimensions (H x W x D) 10.31 in. x 10.5 in. x 10.5 in.
(26.19 cm x 26.67 cm x 26.67 cm)
Housing Outer chamber protective cover is aluminum. Inner
chambers are conductive, tissue equivalent, plastic
Weight 11 lb. (5 kg)
Operating Temperature
0o to 130o F (-16o to 54o C)
Storage Temperature
0o to 132o F (-16o to 56o C)
Relative Humidity 0 to 95% non-condensing
Max. External Pressure 15 psig
Specifications, Preamplifier, Model 977-210-95
Housing Steel, NEMA 4 type
Interface to detector Approximately 5 feet of signal cable and high voltage
cable contained within a flexible conduit. (Other lengths
available).
Interface to Readout Victoreen Comm Loop interface to 942A UDR through
Model 942-200-80 Communications Board. Capable of
driving up to 3000 feet of cable at 4800 Baud.
Interface Cable Requirement Seven (7) conductors, 16 AWG for maximum
preamplifier/readout distance, excluding local alarm
requirements
Power Requirement +15 Vdc @ 250 mA
-15 Vdc @ 50 mA
Auxiliary Alarm Output - 12 Vdc @ 150 mA (maximum)
Auxiliary Analog Output 0 - 10 Vdc, 2 k? min.
Dimensions (H x W x L) 11.5 in. x 8.94 in. x 4.20 in.
(29.21 cm x 22.71 cm x 10.67 cm)
Weight 12 lb. (5.4 kg)
Operating Temperature
0o to 130o F (-16o to 54o C)
Storage Temperature
0o to 132o F (-16o to 56o C)
Relative Humidity 0 to 95% non-condensing
Electronics Life Expectancy
Approximately 104 rads
1-2