Interpretation ID: aiam0263
Vice President Safety and Quality Assurance
American Motors Corporation
Jeep Corporation
940 North Cove Boulevard
Toledo
OH 43601;
Dear Mr. Bernitt: This is in reply to your letter of October 12, 1970, to Mr. Charles A Baker of this office in which you requested an interpretation of the phrase 'effective projected illuminated area.'; Class A turn signal lamps are required by Section S3.1 of Federal Moto Vehicle Safety Standard No. 108, which references SAE Standard J588d in Tables I and III for these lamps. The requirements for the illuminated area of a turn signal lamp are specified in J588d as follows:; >>>'The effective projected illuminated area measured on a plane a right angles to the axle of the lamp must not be less than 12 sq. in. for Class A and 3-1/2 sq. in. for Class B.'<<<; In the 45 degree visibility requirements, this standard further state 'To be considered visible, the lamp must provide an unobstructed projected illuminated area of outer lens surface, including reflex,...'.; Our interpretation of effective projected illuminated area follows: Th effective projected illuminated area is that area of the lens measured on a plane at right angles to the axle of the lamp, including reflex reflector, which is not obstructed by an opaque object such as a mounting screw, mounting ring, or an ornamental basel or trim.; The above interpretation allows the area of rings or othe configurations (raised portions) molded in the lens to be considered part of the total effective area, even if this area does not contribute significantly to the total light output.; Sincerely, Roger Crampton, Director, Office of Operating Systems, Moto Vehicle Programs;