Description
Easy to use, great general purpose radiation detector for a wide array of applications. The Monitor 4 Family of radiation detectors has been put to the test by decades of use in numerous industries.
Detector
Monitor 4:
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.).
Monitor 4EC: Halogen-quenched GM tube, energy compensated sidewall 2mm thin filter. Thin mica window 1.5-2.0 mg/cm2 thick. Effective diameter of window is 9.1 mm (.36 in.).
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)
Energy Sensitivity:
1000 CPM/mR/hr (Cs137). M4EC is the same as M4 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. M4 & M4EC meter scales shown below. Both Detect beta at 50 keV with typical 35% detection efficiency and beta at 150 keV with typical 75% detection efficiency.
Accuracy: Typically ±15% of reading (Cs137)

Range Switch: X1, X10, X100, Battery Check. Meter Face Options
Display: Analog Meter holds full scale in fields as high as 100X maximum reading. CPM & mR/hr scale. Optional SI Scale Meter Available
Audio Indicator: Internally mounted beeper (can be turned off for silent operation).
Power Requirements: 9-volt alkaline battery. Approx. 2,000 hrs. at normal background
Temperature Range: -20° to 55°C (-4° to 131°F)
Weight: M4: 200 g (7.1 oz) M4EC: 224 g (7.9 oz)
Outputs: 3.5 mm 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
Limited Warranty: 1 year limited warranty
Monitor 4 Kits: Build your own Monitor 4! Learn about how a geiger counter works!

