Exploranium GR-135 - Specifications

SAIC Exploranium – GR-135 System Manual page: 44
12.0 SPECIFICATIONS
DETECTORS
a) SODIUM-IODIDE
Detector: Sodium Iodide (Thallium) [NaI(Tl)] 4.0 cu ins ( 65 cm
3
) volume detector
1.5" diam * 2.2” long (38 mm dia x 57mm long) with an integral bi-alkali PMT.
Resolution: Better than 9.0 % FWHM for Cesium 137 at 662 keV.
b) G-M tube : 0.5” diam x 2” long – energy compensated GM tube
Range – 1mR/h to 10R/h for Cesium-137
c) NEUTRON detector (optional): solid state N detector coupled with a miniature PMT
0.86” long by 0.7” diam.
Sensitivity : ITRAP spec – will alarm on a 20KN/s source at 25cms in 5 seconds
d) CZT detector (optional) : 10x10x5mm CZT Capture detector
Resolution: Better than 11.0% FWHM for Barium-133 at 81 keV.
ANALOG TO DIGITAL CONVERTER
Type: Buffered, high speed, high linearity, 8 ΦS - Successive Approximation ADC.
# of channels: 1024
Lower threshold: Internally adjustable – set at 15keV
Upper threshold: Fixed to Ch 1023, all pulses above this level are Cosmic and are accumulated
and displayed in Channel 1024.
ADC Offset: Internally adjustable.
Maximum Count per Channel: 65,535
Dead Time Correction: Automatic, 0.1% precision.
DOSEMETER
Sample time: 1, 2, 3, ... , 10, 20, 30, ... , 60 s
Energy range : 50 keV - 3.0 MeV set by the spectrometer
Meas. units: Selectable R, Sv, Gy.
Meas. range: Sodium-Iodide only: 1 µR/h - 5 mR/h
System may overload at the higher level at a different rate depending on the
isotope. Approximate
maximum levels are 2mR/h for Am-241 and 5 mR/h for
Cs-137.
Meas. Range : G-M tube : 1 µR/h - 1 R/h (10nSv/h – 10mSv/h)