What device should be used to read processed sensitometric strips?

A densitometer is the correct device used to read processed sensitometric strips because it measures the optical density of the film after it has been exposed and processed. Sensitometric strips are utilized in radiography to evaluate the response of the film to radiation exposure, and understanding the density is crucial for determining film sensitivity and contrast.

The densitometer provides quantitative measurements that allow operators to analyze the film's performance and make necessary adjustments to the radiographic process. This is essential for maintaining quality control in radiographic imaging.

Other devices listed, such as a calibrator, scanner, and spectrometer, serve different purposes and measurements. A calibrator is typically used for setting up or adjusting equipment parameters, a scanner is primarily for digitizing images, and a spectrometer measures the spectrum of light or other forms of radiation. None of these functions align with the specific need to measure optical density in sensitometric strips.