RSDetection
User’s Manual
Copyright
©
2016 General Electric Company. All Rights Reserved
S131-200-UM Rev A
Page 21
g
4.1.3
Saturation Characteristics
The saturation of the detector is to ensure that all of the ions generated are measured. If
the bias voltage is not high enough some of these ions recombine, which effectively means
the output is no longer linear with exposure rate. The voltage required to collect all of the
ions generated is termed the saturation voltage, which varies with the dose rate being
measured. A typical saturation curve for dose rate levels of 1.0 and 10.0 mR/h is shown in
Figure 8.
Figure 8 Saturation Curves
To ensure collection of all the ions a voltage of about 13 volts is required if the field is
1mR/h and a bias of 49 volts at 10mR/h. For the standard range of 100mR/h the saturation
voltage is approximately 125 volts, which is well under the 400 volt bias voltage applied to
the detector.
0
0.2
0.4
0.6
0.8
1
1.2
0
10
20
30
40
50
No
rmiliz
ed
O
u
tp
u
t
Bias Voltage
1mR/h
10mR/h
