NCT Manual. - National Car Testing Service

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HEADLAMP AIM
NATIONAL CAR TEST (NCT) MANUAL 2012
Method of Testing
Align the headlamp beam-setter in front of each headlamp in turn, and with the headlamp emitting the dipped beam or the main
beam as appropriate (see Notes below), determine the % gradient of the highest intensity of the beam relative to the plane on
which the vehicle is standing.
NOTES
1. Headlamps fall into three categories as follows:
i
European Type Headlamp – checked on dip beam (see figure 1 for method of test).
ii British-American Type Headlamp – checked on dip beam (see figure 2 for method of test).
iii British-American Type Headlamp – checked on main beam (see figure 3 for method of test).
2. Tyre pressures should be checked and corrected if necessary before the headlamp aim is checked. The
vehicle and the beam-setter should be located on the special headlamp aim checking area within
the test premises.
3. Any headlamp range adjuster must be in the basic setting.
4. If a vehicle is presented with left hand drive headlamps and beam masks, the masks must be installed to
ensure they effectively block any light projection above the 0% horizontal reference line. This would then
show a pattern similar to a mirror image of Fig. 2 and can be checked as on that guide.
5. On vehicles fitted with hydropneumatic suspension, the engine must be idling during this test.
6. The vehicle should be tested without a person in the driver’s seat. If the reading is 0.2% to the limit
(between -0.4% and -0.2%), the test should be carried out with an occupant in the seat. This reading will
be stored in the test results.
ITEM
European Type Headlamp (checked on
dip beam)
British-American Type Headlamp
(checked on dip beam)
British-American Type Headlamp
(checked on main beam)
REASONS FOR FAILURE
1 For headlamps whose centre is not more than 850mm above the
ground, the horizontal cut-off line does not lie between the 0.5%
and 2% horizontal lines.
2 For headlamps whose centre is more than 850mm from the ground,
the horizontal cut-off line does not lie between the 1.25% and
2.75% horizontal lines.
3 The junction of the 15° cut-off and horizontal cut-off line does not lie
between the 0% and 2% vertical lines.
4 The upper edge of the hot spot does not lie between the 0% and
2.75% horizontal lines.
5 The right hand edge of the hot spot does not lie between the 0%
and 2% vertical lines.
6 For headlamps whose centre is not more than 850mm above the
ground, the hot spot centre does not lie between the 0% and 2%
horizontal lines.
7 For headlamps whose centre is more than 850mm above the
ground, the hot spot centre does not lie between the 0% and 2.75%
horizontal lines.
8 The centre of the hot spot does not lie between the 0% and 2%
vertical lines.
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