Monitor 4 Radiation Meter
The Monitor 4 Radiation Detector (M4) 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 senses ionizing radiation by means of a GM (Geiger Mueller) tube with a thin mica window.
The tube is enclosed inside the instrument. When a ray or particle of ionizing radiation enters or passes through the tube, it is sensed electronically and displayed by a red count light. When the switch is in the AUDIO position, the instrument will also beep with each radiation event. About 5 to 25 counts at random intervals (depending on your location and altitude) can be expected every minute from naturally occurring background radiation.
Energy Sensitivity:
Detects alpha down to 2.5 MeV
Typical alpha 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
Detects gamma and x-rays down to 40 keV minimum through the sidewall
Normal background is approximately 10-20 CPM
Gamma Sensitivity:
1000 CPM/mR/hr (referenced to Cs-137)
| 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. |
| 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 |
| Monitor 4EC Energy Sensitivity 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 (referenced to Cs-137) |
| Range Switch: | X1, X10, X100, Battery Check. |
| Operating Range: | 0-.5, 0-5, 0-50 mR/hr and 0-500, 0-5,000, 0-50,000 CPM |
| Accuracy: | ±10% of full scale (referenced to Cs-137). |
| Audio Indicator: | 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 of the Monitor 4: | 178 grams (6.3 oz.) without battery |
| Weight of the Monitor 4EC: | 198.1 grams (7 oz.) without battery |
| Size: | 145 x 72 x 38 mm (5.7 x 2.8 x 1.5 inches). |
| Includes: | Carrying Case, 1 year limited warranty, and CE mark |
| Options: | Belt Clip |