Monitor Radiation Alert® Detectors
With a new ergonomic design, the M4 and M4EC are compact, 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).
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 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.
M4EC: is the Same as Monitor 4 except the energy response for gamma and x-rays through the detector sidewall is flat within +61% or -26% over the range of 40 keV to 100 keV, and within +35% or -17% over the range of 100 keV to 1.3 MeV.