Monitor 4 and Monitor 4EC
The Monitor 4 and Monitor 4EC 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 audible beep sounds with rising radiation levels. The Monitor 4EC offers a more accurate linear reading for gamma and x-rays (above 40 keV).

Specifications
  • 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 2 mm tin filter. Thin mica window 1.5-2.0 mg/cm2 thick.
  • Effective diameter .36"/.92cm
  • Monitor 4 Energy Sensitivity: Detects alpha down to 2.5 MeV; typical detection efficiency at 3.6 MeV is greater than 80%. Detects beta at 50 keV with typical 35% detection efficiency. Detects beta at 150 keV with 75% typical detection efficiency. Detects gamma and xrays down to 10keV typical through the window, 40 keV minimum through the sidewall dectector. Normal background is approx. 10-20 CPM. Gamma Sensitivity: 1000 CPM/mR/hr.
  • Monitor 4EC Energy Sensitivity: Same as Monitor 4 except the energy response 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 (referenced to Cs-137)
  • Accuracy: + 10% of full scale (referenced to Cs-137)
  • Audio Indicator: Internally mounted beeper (can be switched off for silent operation)
  • Range Switch: X1, X10, X100, Battery Check
  • Operating Range: 0-.5, 0-5, 0-50 hR/hr and 0-500, 0- 5000, 0-50,000 CPM
  • Optional SI meter scale: 0-500 žSV/hr and 0-50 mR/hr
  • 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 of the Monitor 4: 178 grams (6.3 oz) without battery
  • Weight of the Monitor 4EC: 198.1 grams (7oz) without battery
  • Size: 145 x 72 x 38mm (5.7 x 2.8 x 1,5 in)
  • Includes: 1 year limited warranty, CE mark, carrying case
  • Options: Stainless steel belt clip (attached to instrument)

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