ANSI C78.21:2011 (R2016)

This standard provides physical and electrical characteristics of the group of incandescent lamps that have PAR and R bulb shapes. Lamps with clear, frosted, and lens end bulbs, with clear and prescription lenses, and with various reflector coatings are covered. Lamps covered in this standard may contain either of two basic types of light sources: an incandescent filament or a tungsten halogen inner bulb. Sunlamps and heat lamps of the R type are included. Lamps with discharge arc tubes are not included. Other groups of incandescent lamp standards are affected by this revision. Please see the normative paragraph below referencing 78.20, 78.22, and 78.23. At the time of issuance of this standard there was no comparable standard published by the International Electrotechnical Commission (IEC).