University of Virginia Library

Sec. 489(53). Head lamp specifications, test and approval.

(a) The commissioner is authorized and required to determine
whether any head lamps of a type sold for use or used upon any
motor vehicle will comply with the requirements of subsection
fifty-one and the specifications set forth in this section and to approve
such head lamp devices and to publish lists thereof by
name and type as it shall determine are lawful herein after a laboratory
test as provided herein.

(b) The commissioner is authorized to accept a certificate of
the United States bureau of standards or some other recognized
testing laboratory having an arrangement with the said bureau
by which appeal may be made to it in case of dispute as to the
findings of such other laboratory which certificate certifies that
a head lamp device is of a type which by laboratory test has been
found to meet the specifications set forth in this section when
properly mounted, adjusted, and equipped with proper candle
power bulbs provided the commissioner is hereby authorized to
refuse approval to any device certified as above which the commissioner
determines will be in actual use unsafe or impracticable
or would fail to comply with the provisions hereof.

(c) Head lamps by laboratory test shall meet the following
requirements and limitations:

1. In the median vertical plane parallel to the lamps on a level
with the centers of the lamps not less than eighteen hundred and
not more than six thousand apparent candle power.

2. In the median vertical plane, one degree of arc below the
level of the center of the lamps, not less than seven thousand two
hundred apparent candle power, and there shall not be less than
seven thousand two hundred apparent candle power anywhere
on the horizontal line through this point, one degree of arc to the
left and to the right of this point.

3. In the median vertical plane, one degree of arc above the

level of the center of the lamps, not more than twenty-four hundred
nor less than eight hundred apparent candle power.

4. Four degrees of arc to the left of the median vertical plane
and one degree of arc above the level of the center of the lamps
not more than eight hundred apparent candle power.

5. One and one-half degrees of arc below the level of the center
of the lamps and three degrees of arc to the left and to the
right, respectively, of the median vertical plane not less than five
thousand apparent candle power nor less than this amount anywhere
on the line connecting these two points.

6. Three degrees of arc below the level of the center of the
lamps and six degrees of arc to the left and to the right, respectively,
of the median vertical plane not less than two thousand
apparent candle power nor less than this amount anywhere on
the line connecting these two points.