Interpretation ID: nht88-3.8

TYPE: INTERPRETATION-NHTSA

DATE: 08/19/88

FROM: ERIKA Z. JONES -- CHIEF COUNSEL NHTSA

TO: PAUL SCULLY -- VICE PRESIDENT PETERSON MANUFACTURING CO.

TITLE: NONE

ATTACHMT: LETTER DATED 04/22/88 TO ERIKA Z JONES, FROM PAUL SCULLY RE INTERPRETATION OF EFFECTIVE PROJECTED LUMINOUS AREA, OCC - 1946

TEXT: Dear Mr. Scully:

This is in reply to your letter of April 22, 1988, asking for a clarification of a letter that this Office sent Wesbar Corporation on March 16, 1988, with respect to the term "effective projected luminous area."

Wesbar had asked whether it could include the "illuminated (by the turn signal bulb) reflex reflector portion of the turn signal lens" (Wesbar's language) in its calculation of the 12 square inch minimum effective projected luminous area required by S4.1 .17 of Safety Standard No. 108. We replied that it could, assuming that the light shines through the reflector. You have pointed out that although a small amount of light escapes through a reflex reflector, the reflector is designed to return light fro m an outside source, rather than to direct light from a source inside the lamp, and that heretofore agency interpretations (e.g. on October 28, 1970, and October 28, 1979) had expressly excluded reflex reflectors from areas included in the calculation of effective projected luminous area. Reflex reflectors are also excluded from the term by SAE J387 Terminology.

We appreciate your calling this matter to our attention. Previous interpretations by this Office clearly indicate that a "reflex reflector" is not to be included in the calculation of effective projected luminous area. We also note that the SAE definit ion (paragraph 2, SAE J594f,

January 1977) is incorporated by reference into Standard No. 108, stating that this item of equipment is one that provides an indication of vehicle presence by reflected light (rather than projected light). We are providing a copy of this letter to Wesbar so that it will be apprised of our reevaluation, and our conclusion that the reflex reflector portion of a lens cannot be included in the calculations of the projected luminous lens area.

I hope this clarifies the matter for you.

Sincerely,