| 摘要 |
<p>Apparatus for deriving from at least one flash of radiation a signal representative of the quantity of radiation contained in the flash or flashes, the apparatus comprising a radiation detector (32) for receiving said flash of radiation and providing an electrical detector output signal (A) which includes a pulse generated in response to said flash, and processing means (36 to 62) arranged to receive said detector output signal and to provide said representative signal, the processing means being operative to substantially remove, in the representative signal, the effect of any D.C. component on which the pulse or psulses may have been superimposed in the detector output signal. In one embodiment, the processing means operates by filtering the detector output signal and passing only its A.C. components. In another embodiment, the signal level in the absence of flashes is measured, the signal level in the presence of flashes is measured, and the measurements are subtracted.</p> |
