Xrite Incorporated 331 Battery Operated B/W Transmission Densitometer. The system has been powered on; however, it has not undergone any diagnostic testing or evaluation. Offers accurate measurement of density in black-and-white photographic materials, ensuring precise color and tonal quality control in various applications. Designed for ease of use, this portable densitometer features a battery-operated design, making it ideal for on-the-go measurements and efficient analysis in both field and laboratory settings. International Buyers – Please Note. The sale of this item may be subject to regulation by the U. Food and Drug Administration and state and local regulatory agencies.