SPECIFICATIONS
MONITOR 4 and 4EC
Detector for the MONITOR 4 and the MONITOR 4EC:
MONITOR 4
- Halogen-quenched uncompensated GM tube Thin mica window is 1.5-2.0 mg/cm2 thick. Approx. 1000
CPM/mR/hr for Cesium 137.
MONITOR 4EC
- Halogen-quenched GM tube. Energy compensated sidewall with 2 mm tin filter. Thin mica window, 1.5-
2.0 mg/cm2 thick. Approx. 1000 CPM/mR/hr for Cesium 137. Energy compensation is only effective through the
sidewall of the GM (refer illustration 1).
MONITOR 4 Energy Sensitivity:
Detects alpha down to 2.5 MeV; typical detection efficiency at 3.6 MeV is greater than 80%.
Detects beta at 50 keV with typical 35% detection efficiency.
Detects beta at 150 keV with typica 75% detection efficiency.
Detects gamma and x-rays down to 10 keV typical
through the window, 40 keV minimum through the
case. (GRAPH 1). Normal background is 5-20 CPM.
MONITOR 4EC Energy Sensitivity:
The energy response to gamma through the detector
sidewall is flat to 61% or -26% over the range of
40 keV to 100 keV, and 35% or -17% over the
range of 100 keV to - 1.3 MeV (referenced to Cs-137).
Detects alpha down to 2.5 MeV; typical detection
efficiency at 3.6 MeV is greater than 80%.
Detects beta at 50 keV with typical 35% detection
efficiency.
Detects beta at 150 keV with typical 75% detection
efficiency.
Detects gamma and x-rays down to 10 keV typical through the window (non-compensated), 40 keV through the sidewall.
Normal background is approx. 5-20 CPM.
Operating Range- Monitor 4 and Monitor 4EC:
0-50 mR/hr and 0-50,000 CPM, or 0-500
μ
Sv/hr and 0-50 mR/hr
Range Switch for the Monitor 4, Monitor 4EC:
X1, X10, X100. Refer to common specifications for more details
6
Graph 1
