Abstract: An X-ray imaging device includes a polychromatic X-ray source (10) and a detector (1, 2) having pixels suitable for operating in photon counting mode within at least one energy window bounded by at least one adjustable threshold, and at least one counter so that each pixel delivers an output dependent on the number of photons received by the pixel in the energy windows during a predetermined time interval. This device includes adjustment element (12) capable of adjusting, in real time, the thresholds of the pixels in succession in various energy windows, and processing element (16) for carrying out, in real time, differential processing of the outputs of the pixels in the various energy windows.

Abstract: Disclosed are a method and a system for the securing of the transmission of data elements between a sensor delivering pulses and a recorder processing these pulses. This method and system are applicable especially to a chronotachograph for heavy road vehicles. The principle of the disclosed method relies on a permanent exchange of enciphered data elements between a recorder module comprising the recorder and a sensor module comprising the sensor. The exchange is done at the initiative of the recorder module which sends command messages X?C(M.sub.C)! enciphered according to a first code C to the sensor module. The sensor module acknowledges the command and then, in turn, generates enciphered return messages X?C'(M.sub.R)!, either in order to indicate the acknowledgement of the command or to transmit pulses from the sensor with a view to their processing by the recorder. The recorder module then deciphers and verifies the return messages (M.sub.