Item #: Monitor 4

Radiation Alert Monitor 4

The M4 is a 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.

Energy Sensitivity: 1000 CPM/mr/hr (Cs137).

Detects alpha down to 2.5 MeV; typical detection detection efficiency at 3.6 MeV is greater than 80%. Detects gamma and x-rays down to 10 keV typical through the window, 40 keV minimum through the case.


  • Carrying Case w/ Belt Clip
  • Size: 209 x 71 x 50 mm (8.2 x 2.8 x 1.9 in.)
Detector Halogen-quenched uncompensated GM tube with thin
mica window 1.5 - 2.0 mg / cm2 thick. Effective
diameter of window is 9.1 mm (.36 in.)
Display Analog Meter holds full scale in fields as high as 100X
maximum reading. CPM & mR/hr scale. Optional
SI Scale Meter Available - Call for Details
Energy Sensitivity 1000 CPM / mR / hr (Cs-137).
Operating Range 0-.5, 0-5, 0-50 mR/hr
0-500, 0-5,000, 0-50,000 CPM or 0-5,
0-50, 0-500 μSv/hr
(SI Scale Meter Option)
Range Switch X1, X10, X100, Battery Check.
Accuracy Typically ±15% of reading (Cs-137)
Audio Indicator Internally mounted beeper (can be turned off for
silent operation).
Temperature Range -20° to 55° (-4° to 131°F)
Weight 224 g (7.9 oz)
Outputs 3.5 mm headphone jack with pulse out
Size 209 x 71 x 50 mm (8.2 x 2.8 x 1.9 in.)
Includes Carrying Case w/ Belt Clip
Options SI Meter Option, Observer Software, Mini-USB
Option w/ USB Observer Software
Monitor 4 Kits
Limited Warranty 1 year limited warranty
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