Which three items are monitored by the Processor Quality Control program?

• A. Base-plus fog density; Mid-density; Density difference
• B. Base plus fog; Image sharpness; Film speed
• C. Developer temperature; Fixer strength; Wash water pH
• D. Exposure time; KV; Filtration

Answer: (A)

Processor quality control for film develops a quick, reliable snapshot of how the processor affects image density. The three things tracked are base-plus fog density, mid-density, and density difference. Base-plus fog density is the density on a film that has no exposure, capturing the baseline shading from the film base and any unwanted fog from the processor or environment. Keeping this baseline low and stable helps ensure that added exposure will produce meaningful contrast rather than being masked by fog. Mid-density refers to the density at a typical mid-point on a calibration or step-wedge film; monitoring this value checks that the processor consistently produces the expected density in the common range used for diagnostic images. Density difference is the span of densities across the test film—essentially how well the processor preserves contrast across the density range. If this changes, it signals adjustments are needed in development chemistry or replenishment to maintain proper image contrast. Other choices involve exposure factors or chemical properties that aren’t the everyday processor performance measure, so they aren’t part of the Processor QC trio.