Re: What is H3,H4, etc

[Peter Henriksen <peterhe@microsoft.com>]

I picked this up on the Swedishbricks mailing list yesterday. It may
enlighten (ahem) you a bit.

- peter, peterhe@microsoft.com, issaquah, wa -
http://www.geocities.com/motorcity/1001
  98 volvo v70 t5 - 5-speed
  94 acura legend gs - 6-speed...

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Date: Thu, 04 Sep 1997 09:16:47 -0400 (EDT)
From: "John Binford (703) 695-7580" <jbinford@acq.osd.mil>
Subject: Euro Headlights vs US Spec...NHTSA response

"John Binford (703) 695-7580" <jbinford@acq.osd.mil> via
SWEDISHBRICKS@SHORE.NET writes :
To those of you that are interested in this sort of thing...I wrote an
e-mail
to jere medlin at nhtsa regarding euro spec lights vs the miserable us
lights
and got this back:



"The U.S. beam pattern offers significant advantages to drivers in the
U.S. who
 must drive at much higher speeds in traffic, and with less stationary
roadway
 lighting than European drivers.  The quantity of light emitted by the
U.S. or
 European lamps is essentially the same,. The European lamp on lower
beam has 
the light aimed closer to the front of the vehicle and spread to the
sides mor
e, while the U.S. pattern is focussed further down the road, is less
wide and 
generally more intense to give greater seeing distance for the higher
speed th
at we travel in traffic.

The H4 bulb that you like is available in the U.S. as the HB2 (trade
number 90
03).  It is essentially identical, but has tighter tolerances in the
dimension
s associated with the filament locations and the fit of the bulb in the
headla
mp's socket.  It is used on many headlamps that are on U.S., European
and Japa
nese vehicles sold in the U.S.  It is archaic, however, relative to
today's U.
S., European and Japanese headlighting technology.  The World vehicle
market i
s striving for new higher efficiency bulbs and many single filament and
dual f
ilament bulbs have been or are being developed to meet the needs of
lighting d
esigners.  The H1 bulb has been replaced by the higher accuracy H7 both
here a
nd in Europe.  The H7 was designed especially for headlamps with the
optical e
lements designed into the reflector rather than the lens.  These
headlamps nee
d very precisely located filaments in order to properly perform.  There
are al
so two new high precision single filament bulbs called the HIR1 and HIR2
(trad
e no's. 9011 and 9012) that are higher output and much more energy
efficient t
hat are intended for these same kind of headlamps.  The bulbs use
special infr
a-red reflective coatings to achieve much higher light flux with less
energy, 
by reflecting the significant infra-red energy back at the filament.
Also, th
ere are three new bulbs that utilize high intensity discharge arc
sources; the
y are the 9500, the D2S and the D2R. These achieve more than twice the
light f
lux of existing bulbs while using about one third the energy.

Additionally, my agency recently completed a significant milestone in
advancin
g toward a globally harmonized beam pattern.  Through a process called
regulat
ory negotiation, NHTSA invited members of the world vehicle and lighting
indus
tries, international vehicle and lighting organizations, safety
advocates, the
 state highway officials and others to participate in a formal
negotiation pro
cess to change the U.S. beam pattern to be capable of being
visually/optically
 aimed.  In doing so, the beam pattern demands about twice as much light
down 
the road as it used to require and must be about twenty degrees wider.
(The pa
ttern is virtually identical to the beams patterns the are achieved by
the hea
dlamps on the 1995 Toyota Camry and the 1995 GM AstroVan.  The Toyota
headlamp
, made by North American Lighting, Farmington MI is one that rated the
highest
 in a Car and Driver subjective headlamp performance appraisal reported
in Nov
ember 1995.)

While the improved pattern tends to look more like a European pattern
(wider a
nd more even), it is aimed much higher (further down the road) than a
European
 beam.  However, the changes accomplished and now implemented in U.S.
law, mak
e this beam pattern capable of being used in headlamp designs that would
be ca
pable of being legal in all countries that accept U.S. or European beam
patter
ns.  In four weeks, I will formally propose to the United Nations in
Geneva th
at the European beam pattern be modified to achieve this higher
performance an
d to make this amended beam pattern the basis for an internationally
harmonize
d standard throughout the World.

The new bulbs mentioned above as well as the HB3 and HB4 (9005 and 9006,
respe
ctively) must be used to achieve this performance.  Bulbs like the
H4/HB2 and 
the HB1 (9004) are not capable of providing the amount of light flux
necessary
.  The HB5 (9007) is marginally capable of achieving that performance.
A new 
dual filament light source being jointly developed by U.S., European and
Japan
ese bulb manufacturers, and intended to have much higher performance, is
close
 to being standardized and within a year will likely be proposed to be
incorpo
rated in national and international regulations.  The heyday of the H4
is long
past."

So hang onto your wallets, troops, cuz we're going to get harmonized.
Does
that mean one single US/Euro/rest of world standard for right hand of
road
drivers...probably not.  
But doesn't it do your heart good to hear that we get significant
advantages of
the Euro spec, notwithstanding the general universal desire for Euro
spec
lights on our US Brix?  This is truly listening to the voice of the
customer.