Quality control film cassette for an x-ray imaging system

An apparatus for evaluating an X-ray imaging system, which apparatus comprises:

• a cassette having a section for receiving a sheet of photographic film;
• an intensifier screen of a material that emits light in response to being stuck by X-rays, and positioned within said cassette so that such emitted light strikes the sheet of photographic film;
• a light sensor within said cassette and producing an electrical signal representing an intensity of light emitted by said intensifier screen;
• an integrator having an input connected to said light sensor and producing an output signal;
• an analog to digital converter having an input coupled to the output of said integrator and producing a digital value corresponding to the output signal of said integrator;
• and
• a light emitting display connected to said analog to digital converter to display the digital value as a multiple digit number which is recorded on the photographic film.