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
  • Panel External Dimensions: 48 in H x 12 in W x 1.5 in D (121.9 cm H x 30.5 cm W x 4 cm D)
  • Panel Weight: 56.6 liters volume per detector

Performance Specifications

  • Gamma Radiation Detection: Meets ANSI N42.35 and IEC 62244
  • Special Nuclear Material (SNM) Detection: 200 g Pu-239 shielded to less than 1% gamma flux
  • Neutron Radiation Detection (GN model only): Meets ANSI N42.35 and IEC 62244
  • 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