Abstract: A flying-spot pencil beam generating unit is arranged under a conveyor. A backscatter detector is located between an upper belt and a lower belt of the conveyor. Thus, this apparatus is set up to be perpendicular. A pencil beam is irradiated upward and scans an object on the belt of the conveyor by the flying-spot pencil beam generating unit, as the conveyor carries the object to be inspected. The backscatter detector gathers Compton scatter X-rays transmitted through the upper belt, as they reflect back from the object. A CPU produces a backscatter image based on the detection signal output from the backscatter detector. The backscatter image is shown on a display unit to enable detection of low-Z materials, such as plastic explosives and narcotics. In addition to the backscatter imaging, the unit may retain use of a transmitted image to thus reliably detect metal-based weapons such as guns.

Abstract: The tomographic testing apparatus employs two data collection modes. One of these modes is a reference data collection mode in which almost all of the prescribed image data of a reference sample is obtained. The reference sample has no defect. The other of these modes is a measurement mode in which a predetermined small number of image data of an inspection sample is obtained. The inspection sample to be tested may have defective portions. The tomographic image of the inspection sample is obtained from the combination of the inspection sample image data and the reference sample image data from which specific data corresponding to the inspection sample image data is deleted.

Abstract: A photomultiplier control circuit includes a circuit for receiving an output signal of a photomultiplier, which detects a light to be measured and converts the detected light to an electric signal in order to generate an output depending on a level of the light to be measured. A light source is used for applying a compensating light to the photomultiplier and a circuit is provided for detecting an average anode current of the photomultiplier. A comparison circuit compares outputs of both circuits and generates the resulting difference output. A control circuit controls the intensity of a light emitted from the light source based on the difference output. The circuit is capable of stabilizing gain fluctuations of a photomultiplier when the incident light is input thereto in the form of a direct current, and also capable of maintaining the accuracy of a photomultiplier when it is employed in measuring tools, etc.

Abstract: A profile measurement apparatus using radiation is disclosed which has three radiation sources and three arcuated multi-channel radiation detectors corresponding to the radiation sources. A rolled steel sheet or strip is conveyed between the radiation sources and the radiation detectors. The sector-shaped radiation beams respectively are radiated by the radiation sources to partially pass through the strip and to respectively incident on the corresponding radiation detectors, which produce profile signals corresponding to the intensities of the incident radiation beams. A microprocessor produces an image signal indicating the sectional shape of an irradiated linear area throughout the entire width of the strip in accordance with the profile signals and causes the display device to display the sectional shape. A mono-channel radiation detector is disposed near the multi-channel radiation detectors to constantly measure a partial thickness of the central portion of the strip.