ChromImage' is allegedly the first commercial flatbed scanner densitometer. The rover carried a dynamic penetrometer and a gamma ray densitometer. The rover carried a dynamic penetrometer and a radiation densitometer. Dot gain can be measured using a densitometer and color bars in absolute percentages. In 1975, it introduced its first densitometer for photographic printing use. The Bone Densitometer Validation experiment was used in support of RR-2. The corresponding measuring device is called a densitometer ("absorptiometer"). The densitometer is basically a light source aimed at a photoelectric cell.