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Monitor 4 Specifications  a ß y xMonitor 4

Monitor 4: Halogen-quenched uncompensated GM tube with thin mica window 1.5-2.0 mg/cm2 thick.
Analog Meter holds full scale in fields as high as 100X maximum reading. CPM/mR/hr scale default. Optional SI Meter Scale option available upon request.
Energy Sensitivity
M4: Detects alpha down to 2.5 MeV; typical detection efficiency at 3.6 MeV > 80%. Detects beta at 50 keV with 35% efficiency. Detects beta at 150 keV with 75% efficiency. Detects gamma and x-rays down to 10 keV through the window, 40 keV minimum through the sidewall. Normal background is approximately 10-20 CPM.

Monintor 4 end window Monitor 4 - USB
        Monitor 4 End Window USB Port on Side of Unit

Operating Range

Monitor 4USB and Monitor 4ECUSB with Mini USB port

0-.5, 0-5, 0-50 mR/hr
0-500, 0-5,000, 0-50,000 CPM or 0-500 µSv/hr
0-50 mR/hr.
Range Switch
X1, X10, X100, Battery Check.
Typically ±15% of reading (referenced to Cs-137)

The M4 and M4EC with Mini USB port on side are compact, ergonomic, general purpose survey meters capable of detecting alpha, beta, gamma, and x-rays over 3 selectable ranges. A red count light flashes and a beep sounds with each event detected. The Monitor 4EC offers a more linear reading for gamma and x-rays (above 40 keV).


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