Patent ID: 7239245

Claim:
A method for monitoring the position of radioactive materials in vehicles, comprising the steps of: powering on a monitoring device, wherein after initializing, the device automatically enters into background mode to acquire and process gamma and neutron detection data so as to obtain and update a background count rate in real time, and wherein an image surveillance system enters into a surveillance state; detecting a vehicle that enters into a monitoring channel, where upon the monitoring device automatically enters into an occupancy mode and performs a data acquisition process for gamma and neutron detection in accordance with the time required by an alarm algorithm so as to obtain respective total count rates; detecting times T 1 and T 2 for the vehicle when it reaches two points with a distance L, and then calculating the vehicle's speed V using T 1 , T 2 and L; setting an alarm threshold based upon the updated background count rate, and sending an alarm signal when the total count rate exceeds the alarm threshold; transmitting the alarm signal to an image surveillance system via a control interface to notify the image surveillance system to start recording, and sending an alarm command to an audio and visual alarm system to send out an alarm; locating the position where the radioactive material is located using methods of horizontal and vertical positioning using the calculated speed.