Re: halogen lamp on x10

["Robert Green" <ROBERT_GREEN1963@xxxxxxxxx>]

"Andrew Gabriel" <andrew@xxxxxxxxxxxxxxxxxxxx> wrote

> "Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> writes:
> > <bcboy@xxxxxxxxxxxxxxxxxx> wrote in message
> >
> >> I do have an IR temp gun.
> >> Should I measure the temp at the fixture around the bulb?
>
> Don't point the gun at a bright light source -- you might damage it.

Interesting.  I've looked at a lot IR temp gun sites in the last few hours
and have not seen that warning.  Do you have a source or URL for that
information?  I know it's true of night vision scopes, and *many* vendors of
image intensifiers warn prospective buyers of the danger of pointing at a
bright light source - namely that it will void your warranty - but that same
warnings are curiously absent from the IR non-contact thermometer sites I
visited.

Is "no bright light" something they only tell you via a little red sticker
on the LCD window AFTER you've purchased the device?  (Gawd I hate that!) As
an amateur videographer checking bright lights is one of the first things
I'd use a remote thermometer for - checking that the TV lights didn't get
too hot!

 > "Figure 2. Halogen lamps have caused more than 500 fires and 30 deaths
> > around the country."
>
> Interesting Figure/Graph, but it's wrong.

Well, there, pilgrim, you gotta better URL?  (-:

I think the Argonne National Lab's chart is more  *right* than *wrong* in
contrasting the various types of bulbs.   You'd have to agree it illustrates
quite clearly how much hotter halogens run compared to incandescent and
especially compact fluorescent bulbs.  The graph is not meant, I suspect, to
be a manufacturer's engineering spec.  They wanted to illustrate the fire
danger from that heat by showing various common ignition points with some
sample bulb heat and wattage ranges mapped to them.

> Halogen bulb wall temperature must be between 250C (for halogen
> cycle to operate) and 350C (above which the lead-in wires through
> the pinch seal will fail). The graph shows 350C-550C.

I'm sorry, but I respectfully disagree about the upper limit. I distinctly
recall reading some bulbs run very hot.  Osram/Sylvania, who manufactures
halogen bulbs, agrees with me on this, putting the top end at 600C and
that's 50C *more* than the ANL chart and 250C hotter than your suggested
upper limit:

| The tungsten-halogen light is similar to conventional non-halogen
| incandescent light in that it employs a tungsten filament in a gas-
| filled, light-transmitting envelope and emits the same type of light.
| The major differences are that a trace of halogen vapor (e.g., iodine
| or bromine) is added to the inert fill gas, the gas pressure (7-8
| ATM) and bulb temperature (250° C to 600° C) are much higher
| than in non-halogen lamps, and the bulb is made of fused quartz
| (silica, SiO2), high-silica glass or aluminosilicate ?hard? glass to
| withstand the high operating pressures and temperatures.  (see:)

http://www.sylvania.com/ConsumerProducts/AutomotiveLighting/Products/Halogen
/HowHalogenWorks.htm

or the shorter http://tinyurl.com/5jql7

General Electric, FWIW, doesn't provide their bulb wall temperature
information on their site, but basically repeat what I told the OP about
things to look for in terms of overheating:

| 5. How can I find the surface temperature of a lamp?

| GE does not publish the surface temperatures of our lamps because
| there are too many factors which can affect the measurement of the
| bulb wall temperature, such as:

| The ambient temperature of the room
|
| Whether or not the surrounding air is still or moving (from
|    wind, a fan, air conditioning, etc.) and at what rate
|
| The specific characteristics of the recessed fixture, such as
|   its baffling, reflection, insulation, and ventilation properties

http://www.gelighting.com/na/business_lighting/faqs/education.htm#1

or the shorter: http://tinyurl.com/8clo7

A torchiere operated in the corner of a room (especially one with bulkheads,
overhangs or other features that trap hot air) is going to run a *lot*
hotter than one that's got good air circulation or is lower to the ground or
has better heat sinking around the reflector.

> Also, Compact Fluorescents are often designed to operate at or
> slightly above 100C. The graph shows something nearer 75C.

I don't even have to search the web to take issue here!!!  I've got a dial/
stem-type darkroom thermometer stuck right against the bulb glass of a 13W
GE CFL that's been burning for 15 minutes.  It is exactly 55C (130F for us
Yanks).  I can unscrew the bulb with my hands while it's lit.  The 45W
(equal to 200W incandescent) does run much hotter, well over 100C.  But the
graph's not far off in my opinion.  And God only knows what formatting
errors occurred if it began life as other than a web document.

Besides, those endpoints are naturally going to be imprecise.  Based on the
context of the page, I think their agenda it to make halogen look bad and CF
look good.  Wouldn't you say the point of the graph is mostly about how MUCH
hotter halogen bulbs are than CFL and even incandescent bulbs?  Perhaps UK
bulbs have different specs since they run at double the voltage that US ones
do.  I can't speak to that point, but may some puddle-jumper could.  :-)

> I believe the UL test requires one of these lamps to fall over
> into/against a muslin cloth without igniting it. Generally, that
> requires a tilt switch to switch off when it tips away from
> vertical, and a shield spaced far enough from the bulb not to
> be above the ignition temperature and to keep the cloth far
> enough from the filament radiant heat source so the bulb radiant
> energy does not get a chance to ignite the cloth before it cools.

That was the old, "easy" UL test.  The new tests are much more stringent.
Don't I get any credit for being right when I said: "Those lamps have
probably killed more people than Billy the Kid?"  :-)

Unquestionably, the more I read about these things (there's an actual
ignition movie here):

http://www.cpsc.gov./vnr/halogen.mpg

the more I am convinced the best way to "check" an old halogen torchiere is
to chuck it.  To my way of thinking, there are enough completely equivalent
(actually superior in terms of cost) lighting techniques that the risk of
using a halogen torchiere isn't balanced by any "must have" feature.

If I did have a pressing need for one, I might wire a second anti-tip
switches (they can stick and fail) and look for a way to strap them to the
wall the way California mandates water heaters be strapped.  If I couldn't
do that I would bolt it to the floor, make sure I had glass and wire shields
over the bulb and that I had nothing in the "fall" radius that was
particularly flammable.

At the State Farm Insurance company site,

http://www.statefarm.com/consumer/vhouse/articles/florlamp.htm

they make these comments about revised UL testing:

Halogen torchiere lamps manufactured after that date [June 1, 1999] will
have to meet the following requirements to bear the UL listing mark:

1. A metal or heat-resistant glass guard must be properly affixed to the
lamp.

2. The lamp must pass a revised fire test -- the cheesecloth drape test. In
this test, a 20-layer pad of cheesecloth is draped over the lampshade for
seven hours with the lamp on. The cloth must not catch fire; no layer should
develop holes;

3. Any lamps not designed with "tip-over switches" must pass a 12-degree
stability test, which measures how prone the light fixture is to being
knocked over.

4. The lamps must pass another fire test in which the lamp is set so it
touches a vertical wall surface covered with untreated cotton terry cloth
for seven hours without the wall igniting.

5. All halogen torchiere lamps must post a date of manufacture on the unit.

That's not guaranteed to be the most recent set of rules, but I think it
shows they've uncovered more routine ignition sources.  People obviously
make cheese in their torchieres, hence the need to test cheesecloth.  :-)

IMHO, if anyone uses halogen torchieres, they are increasing the risk of
fire in their house substantially.  If they're using one of the old lamps
that doesn't meet the new standards above, they're really "playing with
fire!"  (-:

Could we GET further away from the original post?  Sorry "bcboy!" (the OP, I
think, but that was a lot of web pages ago!)

 --
Bobby G.