American National Standard for Electric Lamps - P28 Single-Contact Medium Prefocus-Based Projection Lamps for Base-Down Operation - Dimensions
美国电灯国家标准.底部向下操作用P28单接触介质预聚焦投影灯.尺寸
ANSI C78.1406-2004 (R2008, R2015) establishes the dimensions essential to interchangeability of single-contact medium prefocus-based projection lamps of T10 and T12 bulb sizes.