Patent ID: 7989770
Filing Date: 2011-08-02
Classification: G01N,G01V

Abstract:
1. A control unit for controlling a radiation source, wherein the radiation source being operable to emit radiation for inspecting a moving object passing through an inspection passage, the control unit comprising: a first detector disposed downstream of the radiation source in an advancing direction of the moving object and spaced from the radiation source by a predetermined distance to detect the moving object passing through the inspection passage a second detector disposed under the ground surface of the inspection passage upstream of the first detector in the advancing direction of the moving object, and between the first detector and the radiation source; and a controller for receiving signals from the first detector and the second detector, wherein only when both the first detector and the second detector detect the moving object, the controller controls the radiation source to automatically emit the radiation; wherein the first detector comprises a photoelectric switch, and the second detector comprises a ground induction coil sensor.