| The MONITOR 4MONITOR 4EC are compact, general purpose survey meters capable of detecting alpha, beta, gamma,x-rays over 3 selectable ranges. A redlight flashesa beep sounds with each event detected. The Monitor 4EC offers a more accurate linear reading for gammax-rays above 40 keV. ＊Monitor 4 now available in kit form!＊ Specifications Detector
Monitor 4: Halogen-quenched uncompensated GM tube with thin mica window 1.5-2.0 mg/cm2 thick.
Monitor 4EC: Halogen-quenched GM tube, energy compensated sidewall 2mm tin filter. Thin mica window 1.5-2.0 mg/cm2 thick.
Display
Analog Meter Scale.
Monitor 4 Energy Sensitivity
Detects alpha down to 2.5 MeV; typical detection efficiency at 3.6 MeV is > 80%.
Detects beta at 50 keV with typical 35% detection efficiency.
Detects beta at 150 keV with 75% typical detection efficiency.
Detects gammax-rays down to 10 keV typical through the window, 40 keV minimum through the sidewall of the detector.
Normal background is approximay 10-20 CPM. | Gamma Sensitivity: | Operating Range | 1000 CPM/mR/hr referenced to Cs-137
Energy Sensitivity for the 4EC is the Same as Monitor 4 except the energy response for gammax-rays through the detector sidewall is flat within +61% or -26% over the range of 40 keV to 100 keV,within +35% or -17% over the range of 100 keV to 1.3 MeV.
| 0-.5, 0-5, 0-50 mR/hr
0-500, 0-5,000, 0-50,000 CPM or 0-500 ?Sv/hr
0-50 mR/hr.
Range Switch
X1, X10, X100, Battery Check.
Accuracy
Typically ±15% of reading referenced to Cs-137 |
Monitor 4
 |
Monitor 4EC
 | Audio
Internally mounted beeper can be switched off for silent operation.
Anti-Saturation
Meter will hold at full scale in fields as high as 100 times the maximum reading.
Power Requirements
One 9-volt alkaline battery. Battery life is up to 2,000 hours at normal background radiation levels
Temperature Range
-20° C to 55° C -4° F to 131° F.
Weight
M4: 178 grams 6.3 oz. without battery
4EC: 198.1 grams 7 oz. without battery
Size
145 x 72 x 38 mm 5.7 x 2.8 x 1.5 in.
Warranty
1 year limited warranty
Monitor 4 Kits
Build your own Monitor 4! Learn about how a geiger counter works!
Includes: All parts required to build a Monitor 4, AssemblyIllustration booklets. Accessories | | | | Carrying Case | Observer Software | |
