标准号:ANSI IT7.221-1989(R1998)
中文标准名称:视听系统。高架投影机。幻灯片和幻灯片帧。尺寸
英文标准名称:Audiovisual Systems - Overhead Projectors - Transparencies and Transparency Frames - Dimensions Reaffirmation and Redesignation of ANSI /ISO 7943.2-1987(R1992), ANSI/NAPM IT7.221-1989 (R1994); ISO 7943.2-1987(R1997