307.128. Motorcycle headlamp modulation permitted, when--labeling requirements. - Missouri Statutes

Motorcycle headlamp modulation permitted, when--labeling requirements.

307.128. 1. A headlamp on a motorcycle may be wired to modulateeither the upper beam or the lower beam from its maximum intensity to alesser intensity provided that:

(1) The rate of modulation shall be two hundred forty plus or minusforty cycles per minute;

(2) The headlamp shall be operated at a maximum power for fifty toseventy percent of each cycle;

(3) The lowest intensity at any test point shall not be less thanseventeen percent of the maximum intensity measured at the same point;

(4) The modulator switch shall be wired in the power lead of the beamfilament being modulated and not in the ground side of the circuit;

(5) Means shall be provided so that both the lower beam and the upperbeam remain operable in the event of a modulation failure;

(6) The system shall include a sensor mounted with the axis of itssensing element perpendicular to a horizontal plane. Headlamp modulationshall cease whenever the level of light emitted by a tungsten filamentoperating at three thousand degrees kelvin is either less than two hundredseventy lux of direct light for upward pointing sensors or less than sixtylux of reflected light for downward pointing sensors. The light ismeasured by a silicon cell type light meter that is located at the sensorand pointing in the same direction as the sensor. A photo gray card isplaced at ground level to simulate the road surface in testing downwardpointing sensors;

(7) Means shall be provided so that both the lower and upper beamfunction at design voltage when the headlamp control switch is in eitherthe lower or upper beam position when the modulator is off.

2. Each motorcycle headlamp modulator not intended as originalequipment, or its container, shall be labeled with the maximum wattage, andthe minimum wattage appropriate for its use. Additionally, each suchmodulator shall comply with the provisions of subdivisions (1) to (7) ofsubsection 1 of this section when connected to a headlamp of themaximum-rated power and headlamp of the minimum-rated power, and shallprovide means so that the modulated beam functions at design voltage whenthe modulator is off. Instructions, with a diagram, shall be provided formounting the light sensor including location on the motorcycle, distanceabove the road surface, and orientation with respect to the light.

(L. 2009 H.B. 253)