The purpose of this test is to measure the resolution capability of a cathode ray display tube. Raster scan is the most widely used method of displaying information on a CRT. The test described in this section gives a figure of merit related to the resolution of the display tube. The resolution is dependent on: 1. The electron beam distribution as it is focussed onto the phosphor screen. 2.Electron scatter and light scatter due to the granular nature of the phosphor and the aluminum backing of the screen. 3. Saturation of the phosphor. 4. Internal reflections within the faceplate and panels mounted onto the faceplate. 5. Optical effects of coatings@ etchings@ etc.@ on the faceplate and panel. Other external influences including ambient light are not addressed in this method. As well@ the transfer characteristicsof the viewing system are not considered.