Monitor 4 Survey MeterMonitor 4 Survey Meter 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. Specifications: Monitor 4: Halogen quenched uncompensated GM tube with 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