Interpretation ID: 2352y
Manager, Automotive Engineering
Lighting Control Dept.
Stanley Electric Co. Ltd.
2-9-13, Nakameguro, Meguro-ku
Tokyo 153, Japan
Dear Mr. Chikada:
This is in reply to your letter of August 9, l989, to the former Chief Counsel, Erika Jones. You have asked for an interpretation of two of the amendments of May 9, 1989, to Federal Motor Vehicle Safety Standard No. l08. We have delayed answering you until action could be taken on petitions for reconsideration of the May 9 amendments. This action was taken on February 8, 1990 (copy of Federal Register notice enclosed), and the new amendments adopted then, effective March 12, l990, include definitions of "Direct reading indicator" and "Remote reading indicator."
Section S7.7.5.2(a)(l)(iii) states in pertinent part that each graduation on a Vehicle Headlamp Aiming Device (VHAD) "shall indicate a linear movement of the scale indicator of not less than 0.05 in. (1.27 mm) if a direct reading analog indicator is used," and "if a remote reading indicator is provided, it shall represent the actual aim movement in a clear, understandable format." Your letter depicts two devices identified as a "direct reading analog indicator" and a "remote reading indicator", and you ask for confirmation that each conforms with the requirements of the section.
Preliminarily, we observe that your drawings do not depict how the devices are determined to be "direct" and "remote". Our interpretation of your "direct indicator" is that the location of the bubble is proportional to the slope of the surface and the adjustment, i.e., as the angle of aim changes, so does the location of the bubble, and its location relative to the graduations changes in proportion to the angle of aim. Our interpretation of your "remote indicator" is that the location of the bubble represents the difference between the correct setting and the actual setting of the adjustment, and the reading may or mau not be proportional to the difference. Based on these interpretations, either device would appear to be capable of meeting the recently adopted definitions of direct and remote reading indicators.
For example, if either device were mounted in its entirety on the headlamp to sense vertical attitude, the devices would both appear to be capable of directly reading the aim of the headlap and also appear to be capable of accommodating variations in floor slope. In this case, each device would meet the definition of a "direct reading indicator". And if either device were mounted in whole or in part elsewhere than on the headlamp or its aiming or mounting equipment (e.g., mounted on the firewall, inner fender panel, instrument panel), and linked mechanically to the headlamp such that its vertical aim was correctly displayed on the indicator, each device would also appear to meet the definition of a "remote reading indicator".
Paragraph S7.7.2 requires in pertinent part that each headlamp aiming mechanism allow aim inspection and adjustment, and be accessible for such uses "without removal of vehicle parts, except for protective covers removable without the use of tools." You have asked whether the protective cover mentioned includes the cover to protect the spirit level when it is a component of the VHAD. The answer is no. The protective cover mentioned is one intended to shield the entire VHAD, or a cover that is not transparent and inhibits the proper aim inspection and adjustment. A transparent cover or transparent portions of a cover protecting the indicator (in your case, the spirit level of your direct reading indicator) is not required to be removable. However, if your remote reading indicator has a transparent protective cover, it would be required to be removable without the use of tools to gain access to the dial indicator, if the indicator is not adjustable with the cover in place.
I hope that this answers your questions.
Sincerely,
Stephen P. Wood Acting Chief Counsel
Enclosure ref:l08 d:3/l5/90