Ergonomic, Analog, Inexpensive
The Monitor 4 and Monitor 4EC are compact, general purpose survey meters capable of detecting gamma, and x-rays over 3 selectable ranges. A red count light flashes and a beep sounds with each event detected. The Monitor 4EC, (energy compensated) offers a more accurate linear reading for gamma and x-rays above 40 keV. Gamma sensitivity is typical of a G-M detector: 1000 CPM/mR/hr, referenced to Cs-137. Energy Sensitivity for the 4EC is the same as Monitor 4, but the energy response for gamma and x-rays through the detector sidewall is flat within +61% or -26% ov
Monitor 4 Survey Meter Specifications:
Detector
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.
Effective diameter of window is 9.1 mm (.36 in.).
Display
Analog Meter Scale.
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 x-rays down to 10 keV typical through the window, 40 keV
minimum through the sidewall of the detector.
Normal background is approximately 10-20 CPM.
Gamma Sensitivity:
1000 CPM/mR/hr (referenced to Cs-137)
Monitor 4EC Energy Sensitivity
Energy Sensitivity for the 4EC 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.
Operating Range
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.
Accuracy
±15% of full scale (referenced to Cs-137)
Monitor 4 Response Curve
Monitor 4EC Response Curve
Audio
Internally mounted beeper (can be switched off for silent operation).
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
Monitor 4: 178 grams (6.3 oz.) without battery
Monitor 4EC: 198.1 grams (7 oz.) without battery
Size
145 x 72 x 38 mm (5.7 x 2.8 x 1.5 in.)
Warranty
1 year limited warranty
Accessories
Monitor 4 Analog Survey Meter Order Online SSL Encrypted
Monitor 4EC Analog Survey Meter, Energy Compensated Order Online SSL Encrypted
