Vehicle Contamination Portal Monitors, G5340 Series

The ANTECH G5340 Series Contamination Vehicle Portal Monitors are designed to detect gamma ray emitting radioactive substances in a range of applications which includes recycled materials and general cargo contained in moving vehicles. They are suitable for road and rail applications and are available in 2 metre high (Model G5342-400), 3 metre high (Model G5343-600), and 4 metre high (Model G5344-800) configurations.

The technology behind the ANTECH Contamination Portal Monitors is derived from work performed at the Los Alamos National Laboratory (LANL) in the United States and implemented in the late 1980s by Jomar Systems. Since the transfer of this technology to ANTECH, extensive improvements have been made and ANTECH portal monitoring technology represents the current state of the art for contamination monitoring.

VCPM Datasheet


Measurements are made using plastic scintillator gamma ray detectors. The signals from these detectors are amplified using propriety ANTECH charge sensitive amplifiers for measurement by counters that are connected to the system microprocessor controller.

Occupancy sensors on either side of the carriage way detect when the portal is occupied by a vehicle and enable the system to distinguish between contaminated material and high background radioactivity.

The operation of the G5340 Series is automated by an onboard microprocessor controller with associated counting electronics comprising a flexible Master Control Unit (MCU). The MCU is located close to the plastic scintillator detectors and performs input monitoring, background discrimination, alarm initiation and system diagnostic testing.

Features & Benefits


  • Plastic scintillator detectors that can detect unshielded gamma ray emitting sources of less than 10 micro-Curies of typical fission products, industrial radionuclides or medical radionuclides
  • Two pillars that house the plastic scintillator detectors and MCU, and provide shielding to reduce background radioactivity
  • Remote Control Panel (RCP) that confirms correct operation of the system, alerts the operator to contamination, and contains the battery, battery charger, alarm systems, printer connection and LED display
  • User selectable alarm provided as a visual, audio or electronic signal


  • Simple to install, requiring only a 200 mm (7.87 in) deep concrete base to which the pillars are attached with anchor bolts
  • Can operate in extremes of temperature and humidity, so is suitable for use in harsh environmental conditions
  • Inherently low maintenance due to lack of moving parts
  • The RCP can be up to 100 metres (328.08 feet) away from the pillars without degrading performance
  • The RCP can be wall mounted in a convenient position
  • The RCP can be set to print a daily summary of events to provide a permanent record for the operator
  • Low rate of false alarms (typically less than 1 in 10,000) even at the higher sensitivity. Sensitivity and the resulting false alarm rate can be set by the user.
G5342-400 G5343-600 G5344-800
External dimensions (H x W x D) 2200 mm x 600 mm x 600 mm (86.61 in x 23.62 in x 23.62 in) 3200 mm x 600 mm x 600 mm (125.98 in x 23.62 in x 23.62 in) 4200 mm x 600 mm x 600 mm (165.35 in x 23.62 in x 23.62 in)
Plastic scintillator gamma ray detectors  2 in each pillar 3 in each pillar 4 in each pillar