New headlamp testing standard details revealed
DVSA has provided more detail on the new “simpler, more consistent” headlamp standard for vehicle testing (Transport Operator, January/February), which is being rolled out from 1 April 2015.
The new standard will align the headlamp aim test with European directives 2010/48/EU and 2014/45/EU, and will: “extend the tolerance band for headlamp centres up to 850mm and change the requirements to test the ‘image break’ point.”
In its ‘Moving On’ blog, DVSA explained: “Currently we try to define the ‘image break’ point on the screen to ensure it’s within the 0 per cent and 2 per cent vertical lines.
“Pinpointing this has become more and more difficult because of the design of modern dipped beam light sources and the placement of the hot spot within the beam pattern.
“The new standard requires us to look for any white light in the dazzle zone formed by the 0 per cent vertical and the 0.5 per cent horizontal lines.”
The agency continued: “Any white light in the box formed by the 0 per cent vertical and 0.5 per cent horizontal is likely to dazzle oncoming traffic…
“If a beam is required to have a ‘kick up’, this must show on the headlamp aim tester screen. Lots of headlamps have a flat beam pattern or just a small ‘kick up’ and some can be presented with beam deflectors.”
DVSA said that the vehicle would fail the test if white light were to show in the dazzle zone, or if the beam image were to contain a ‘kick up’ that was not visible on the screen.
The method of checking the aim of the horizontal cut off remains the same, the agency added – but the lower limit for headlamps up to 850mm has changed from 3.25 per cent to 4 per cent.
“For headlamp centre up to 850mm, this would fail if the horizontal cut off was above the upper limit of 0.5% (as it always has)” or if “the horizontal cut off was below the lower limit of four per cent.”
The new method has undergone testing by Loughborough University, which concluded that there would be no adverse impact on road safety.
