Fissures are double folds of pleura that divide the lung into lobes. There are three lobes in the right lung and two in the left lung. The lobes are further divided into segments and then into lobules, which are hexagonal divisions of the lungs that are the smallest visible subdivision.
Spectrophotometers are color measurement devices used to capture and evaluate color, including specification and communication of color, and monitoring color accuracy.
If a photoelectric cell instead of the eye is used to compare intensities, the instrument is called a photoelectric colorimeter. In colorimetry, frequently the entire visible spectrum (white light) is used, and consequently the complementary colour of the one absorbed is observed as transmitted light. If monochromatic light or a narrow band of radiation is used, the instrument is called a spectrophotometer.