Microdensitometer is a scientific instrument that measures the optical density of very small samples. Some synonyms for microdensitometer include microspectrophotometer, high-resolution spectrophotometer, microphotometer, and microspectrometer. These instruments are used in a variety of scientific fields, including biology, physics, and engineering. They are typically used to measure the spectral or spatial characteristics of tiny samples such as biological tissues, thin films, or microscopic particles. Microspectrophotometer and high-resolution spectrophotometer are the most common synonyms for microdensitometer. They are often used interchangeably, but the latter term usually refers to a device with higher precision and better resolution.