The VM400BGN is a versatile radiation portal monitor for screening a wide variety of conveyance, from passenger vehicles to heavy, wide-load trucks. This RPM offers exceptional gamma and neutron sensitivity making it ideal for border crossings, ports, airports, critical infrastructure, and nuclear facilities.


  • Drive-through radiation portal monitor for passenger vehicles, trucks, containers, and heavy wide-load trucks

  • Superior gamma and neutron sensitivity

  • Automatic inspection operation

  • Nuclide identification capabilities with optional NaI(TI) detectors

Physical Specifications

  • Operating Configurations: Drive-through radiation portal monitor
    • VM400BG (model) for gamma detection
    • VM400BGN (model) for gamma and neutron detection
  • Pillars: Primary and secondary
  • Number of Gamma Detectors: 4 detectors; 2 per panel
  • Gamma Detection Material: Polyvinyltoluene (PVT) plastic scintillator
  • Number of Neutron Detectors (GN model only): 4 detectors; 2 per panel
  • Neutron Detector Material (GN model only): B-10
  • External Dimensions: 120 in H x 40 in W x 12 in D (304 cm H x 102 cm W x 30.5 cm D)
  • Weight: 2,122 lbs. (963 kg) including pedestal

Performance Specifications

  • Special Nuclear Material (SNM) Detection: 200 g Pu-239 shielded to less than 1% gamma flux
  • Gamma False Alarm Rate: Less than 1 in 1,000 passages (typical)
  • Neutron False Alarm Rate (GN model only): Less than 1 in 1,000 passages (typical)


  • Inspection Speed: 5 mph (8 km/h) nominal
  • Ports: RS232, Ethernet

Environment / Safety

  • Temperature: -29 °F to 122 °F (-34 °C to 50 °C)
  • Humidity: 5 to 95% non-condensing
  • Environmental Protection: IP65