Automatic system for continuously calibrating a gamma camera

An automatic system for the continuous re-calibration of a gamma ray camera comprising a scintillation crystal, a light conductor disposed proximate said crystal, a plurality of signal channels each including a photomultiplier disposed proximate said conductor, said automatic system comprising,

• a device means for forming a reference light signal for the photomultipliers, said device means being disposed among said photomulitipliers, a generator means coupled to said device means for controlling the pulsed periodical calibration operation,
• a plurality of cooperating circuits means coupled to said generator means for stabilizing the gain factor in each of said channels respectively at a value between a lower limit and an upper limit of a range about an initial gain factor, each of said stabilizing means comprising a resistance bridge including a plurality of resistors coupled to said photomultipliers, and means for changing the ratio of said resistors;
• and means for determining said initial gain factor with respect to only said reference light signal.