Comparator, Optical Inspection.
DEPARTMENT OF THE ARMY WASHINGTON D C
Pagination or Media Count:
Two identical thin lenses are placed side by side and in the same plane level above work being examined which is located at approximately the lenses focal length. The observers eye is at a controlled center between the lenses and at a distance about double their focal length. The observer sees alternately two magnified images of the work with one eye, so as to compare a standard with a sample.
- Test Facilities, Equipment and Methods