Thermo Scientific RO-20, Operating Manual

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1-2 RB-XXX-XXXXXX E RO-20
Löw 08.10.2008
1.2 Measuring Units
The RO-20 has the ranges labeled in exposure rate R/h.
The ranges are 50 R/h,5 R/h and 500mR/h,50mR/h,5 mR/h.
The RO-20 chamber is designed to have a flat energy response in roentgen units.
Use the procedure given in this manual for calibration of the instrument. The calibration
controls on the main circuit board are marked from 5 through 50 k, which corresponds to the
5 ranges (expressed in R/h).
1.3 Detector Specifications
1.3.1 Size
2.84-inch inside diam, 13.4 in
3
volume (7.21 cm diam, 220 cm
3
).
1.3.2 Fill
Air, vented to atmospheric pressure.
1.3.3 Wall
0.20 in. (0.51 cm) conductive plastic approximately 640 mg/cm
2
inside
0.063-in. wall aluminum case, making approximately 1000 mg/cm
2
total thickness.
1.3.4 Window
Two layers (one on the chamber, one on the can) 0.001-in. (25 micron) mylar, approximately
7 mg/cm
2
total.
1.3.5 Beta Shield
Sliding shield on bottom of case with positive friction lock. Approximately 1000 mg/cm
2
(5/16 in. phenolic).
1.3.6 Radiation Detected
Beta, gamma and x-ray.
1.3.7 Photon Energy Response
The nominal photon energy response is shown in Figure 1-2 .