Fluke Biomedical 945A User 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)