An X-ray imaging system or radiographic imaging system includes a radiation generating apparatus and a radiographic imaging apparatus. An ionization chamber device is external to the radiographic imaging apparatus, for detecting a dose of the radiation transmitted through an object. Dose sensors are incorporated in the radiographic imaging apparatus, for detecting a dose of the radiation transmitted through the object. An exposure control unit is disposed with the radiation generating apparatus, for shutting off application of the radiation from the radiation generating apparatus according to a detection signal from the ionization chamber device or dose sensors. The ionization chamber device is communicably coupled with the radiation generating apparatus. An operating state of the ionization chamber device and dose sensors is acquired by monitoring, so failure of simultaneous inputting of their detection signals to the exposure control unit is prevented.