The ACR-060 provides the controlled diffuse illumination that is necessary for making ambient contrast ratio measurements of displays of all sizes, from cell phone displays to projection TVs. The ACR-060 consists of a 6-inch sampling sphere with an internal tungsten halogen light source and a sphere monitor photo detector. The sampling sphere is placed in front of the display being tested, while the display is measured by your spot photometer though a view port on the sampling sphere.