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Inexpensive LUX meter from China to measure your bike lamp's output



 
 
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  #1  
Old February 21st 18, 04:31 AM posted to rec.bicycles.tech
Andre Jute[_2_]
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Posts: 8,705
Default Inexpensive LUX meter from China to measure your bike lamp's output

Inexpensive LUX meter from China to measure your bike lamp's output. Stumbled across this while I was looking for something else. No recommendation, but I remembered you guys were discussing lux ratings not too long ago.

https://www.aliexpress.com/store/pro...4b9c46a0WLmNTx

Andre Jute
Always helpful
Ads
  #2  
Old February 21st 18, 08:21 AM posted to rec.bicycles.tech
Jeff Liebermann
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Posts: 2,833
Default Inexpensive LUX meter from China to measure your bike lamp's output

On Tue, 20 Feb 2018 20:31:59 -0800 (PST), Andre Jute
wrote:

Inexpensive LUX meter from China to measure your bike lamp's output. Stumbled across this while I was looking for something else. No recommendation, but I remembered you guys were discussing lux ratings not too long ago.

https://www.aliexpress.com/store/pro...4b9c46a0WLmNTx

Andre Jute
Always helpful


Sigh. I see that you haven't been reading my rants. That's the exact
model that I've recommended in at least three of my previous rants on
the topic. Also available on eBay and Amazon.
https://www.ebay.com/itm/222318701790
or search for "lux meter".

Also from several revious rants, if you draw a 1.13meter (44.5inch)
diameter circle on the wall, and shine your bicycle head light or
flashlight on the wall until it fills the circle, the lux meter will
read directly in lumens. It works because the area of the circle is 1
square-meter and:
1 lux = 1 lumen/sq-meter
If you light produces a non-circular spot on the wall or an uneven
pattern, just guess(tm) until you have a spot that looks roughly like
1 square-meter. No warranty for accuracy expressed or implied.

Lux Sit (Let let there be light).

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #3  
Old February 21st 18, 09:30 AM posted to rec.bicycles.tech
Andre Jute[_2_]
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Posts: 8,705
Default Inexpensive LUX meter from China to measure your bike lamp's output

On Wednesday, February 21, 2018 at 8:21:42 AM UTC, Jeff Liebermann wrote:
On Tue, 20 Feb 2018 20:31:59 -0800 (PST), Andre Jute
wrote:


Sigh. I see that you haven't been reading my rants. That's the exact
model that I've recommended in at least three of my previous rants on
the topic. Also available on eBay and Amazon.
https://www.ebay.com/itm/222318701790
or search for "lux meter".


The more sources the better, then.

Andre Jute
I like your DIY calibration test, though.
  #4  
Old February 21st 18, 04:14 PM posted to rec.bicycles.tech
Jeff Liebermann
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Posts: 2,833
Default Inexpensive LUX meter from China to measure your bike lamp's output

On Wed, 21 Feb 2018 01:30:26 -0800 (PST), Andre Jute
wrote:

On Wednesday, February 21, 2018 at 8:21:42 AM UTC, Jeff Liebermann wrote:
On Tue, 20 Feb 2018 20:31:59 -0800 (PST), Andre Jute
wrote:


Sigh. I see that you haven't been reading my rants. That's the exact
model that I've recommended in at least three of my previous rants on
the topic. Also available on eBay and Amazon.
https://www.ebay.com/itm/222318701790
or search for "lux meter".


The more sources the better, then.


I have 2 other Lux meters. Both have removable sensor "pucks" which
allegedly make measurements easier. I've compared readings between
the three meters and find that they are all fairly close to each
other. I don't have a calibrated source, so I can't determine their
accuracy. The UNI-T UT383 above is the most useful because it's the
only one that has a peak reading feature. I mark the diameter of my
one square meter circle on the wall, turn on the test flashlight or
headlight, and walk towards the wall until the spot has the same
diameter. I then turn off the light, and the highest reading remains
on the display. Very handy for doing measurements without an
assistant.

If you want better accuracy, measure the hot spot in the center and
the brightness at the edges. I usually give it 33% above the edge
value, although 50% is probably close enough.

I like your DIY calibration test, though.


You might want to measure your various lights and headlights and see
how they compare with the published specs. If enough people do that,
maybe we can see an end to inflated lumens specs. I measured about 15
assorted lights and flashlights, but nobody seemed interested.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #5  
Old February 21st 18, 10:16 PM posted to rec.bicycles.tech
Roger Merriman[_4_]
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Posts: 141
Default Inexpensive LUX meter from China to measure your bikelamp's output

Jeff Liebermann wrote:
On Wed, 21 Feb 2018 01:30:26 -0800 (PST), Andre Jute
wrote:

On Wednesday, February 21, 2018 at 8:21:42 AM UTC, Jeff Liebermann wrote:
On Tue, 20 Feb 2018 20:31:59 -0800 (PST), Andre Jute
wrote:


Sigh. I see that you haven't been reading my rants. That's the exact
model that I've recommended in at least three of my previous rants on
the topic. Also available on eBay and Amazon.
https://www.ebay.com/itm/222318701790
or search for "lux meter".


The more sources the better, then.


I have 2 other Lux meters. Both have removable sensor "pucks" which
allegedly make measurements easier. I've compared readings between
the three meters and find that they are all fairly close to each
other. I don't have a calibrated source, so I can't determine their
accuracy. The UNI-T UT383 above is the most useful because it's the
only one that has a peak reading feature. I mark the diameter of my
one square meter circle on the wall, turn on the test flashlight or
headlight, and walk towards the wall until the spot has the same
diameter. I then turn off the light, and the highest reading remains
on the display. Very handy for doing measurements without an
assistant.

If you want better accuracy, measure the hot spot in the center and
the brightness at the edges. I usually give it 33% above the edge
value, although 50% is probably close enough.

I like your DIY calibration test, though.


You might want to measure your various lights and headlights and see
how they compare with the published specs. If enough people do that,
maybe we can see an end to inflated lumens specs. I measured about 15
assorted lights and flashlights, but nobody seemed interested.


Both lux and Lumens stated are a guide really, or to put it another way,
I’ve noticed more difference from the beam shape than the claimed
Lux/lumens which makes sense since Lux is for bikes at least measured at
the 10 meter mark, and Lumens is generally what ever the led will can
produce.

What neither will tell you is how they light the trail/road, or to put it
another way seeing the light working is a far better test than lumen/Lux
stats.

And to be honest it’s best to see it as you where rather than seeing screen
shots as beam shots are difficult if not impossible to do fairly since
human eye and cameras do differ in this regard so some lights look much
better or worse in beamshots.

Roger Merriman

  #6  
Old February 22nd 18, 12:52 AM posted to rec.bicycles.tech
Andre Jute[_2_]
external usenet poster
 
Posts: 8,705
Default Inexpensive LUX meter from China to measure your bike lamp's output

On Wednesday, February 21, 2018 at 4:14:21 PM UTC, Jeff Liebermann wrote:
On Wed, 21 Feb 2018 01:30:26 -0800 (PST), Andre Jute
wrote:

On Wednesday, February 21, 2018 at 8:21:42 AM UTC, Jeff Liebermann wrote:
On Tue, 20 Feb 2018 20:31:59 -0800 (PST), Andre Jute
wrote:


Sigh. I see that you haven't been reading my rants. That's the exact
model that I've recommended in at least three of my previous rants on
the topic. Also available on eBay and Amazon.
https://www.ebay.com/itm/222318701790
or search for "lux meter".


The more sources the better, then.


I have 2 other Lux meters. Both have removable sensor "pucks" which
allegedly make measurements easier. I've compared readings between
the three meters and find that they are all fairly close to each
other. I don't have a calibrated source, so I can't determine their
accuracy. The UNI-T UT383 above is the most useful because it's the
only one that has a peak reading feature. I mark the diameter of my
one square meter circle on the wall, turn on the test flashlight or
headlight, and walk towards the wall until the spot has the same
diameter. I then turn off the light, and the highest reading remains
on the display. Very handy for doing measurements without an
assistant.

If you want better accuracy, measure the hot spot in the center and
the brightness at the edges. I usually give it 33% above the edge
value, although 50% is probably close enough.

I like your DIY calibration test, though.


You might want to measure your various lights and headlights and see
how they compare with the published specs. If enough people do that,
maybe we can see an end to inflated lumens specs. I measured about 15
assorted lights and flashlights, but nobody seemed interested.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


Even at such an attractive price, I'm not buying the meter, Jeff. For health reasons, I no longer go for those middle watches of the night rides, as no one will go with me and it's stupid for me to ride alone on totally empty lanes. So I have nothing to measure for.

In any event, by subjective measurement a la Roger's post, I judge I already have what on balance I consider BUMM's best lamp, the first series Cyo R (I also have reflectorless version but it isn't as good in lanes as the R, and I have the Fly-E with supposedly the same optics but with a very nasty hotspot), so I'm not even in the market for new lamps.

Andre Jute
It's a dull life if you can't even think of a tool you want
  #7  
Old February 22nd 18, 06:16 AM posted to rec.bicycles.tech
Tosspot[_3_]
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Posts: 1,180
Default Inexpensive LUX meter from China to measure your bike lamp'soutput

On 22/02/18 01:52, Andre Jute wrote:

snip

In any event, by subjective measurement a la Roger's post, I judge I already have what on balance I consider BUMM's best lamp, the first series Cyo R (I also have reflectorless version but it isn't as good in lanes as the R, and I have the Fly-E with supposedly the same optics but with a very nasty hotspot), so I'm not even in the market for new lamps.


Three of those dies before I gave up on them, all inside 18 months each.
Do you go out in the rain much?
  #8  
Old February 22nd 18, 08:13 AM posted to rec.bicycles.tech
Andre Jute[_2_]
external usenet poster
 
Posts: 8,705
Default Inexpensive LUX meter from China to measure your bike lamp's output

On Thursday, February 22, 2018 at 6:16:19 AM UTC, Frank Leake wrote:
On 22/02/18 01:52, Andre Jute wrote:

snip

In any event, by subjective measurement a la Roger's post, I judge I already have what on balance I consider BUMM's best lamp, the first series Cyo R (I also have reflectorless version but it isn't as good in lanes as the R, and I have the Fly-E with supposedly the same optics but with a very nasty hotspot), so I'm not even in the market for new lamps.


Three of those dies before I gave up on them, all inside 18 months each.


You want to be careful what you say here, Frank. The slightest suspicion that you think every BUMM lamp, including the ancient lethal glimmerers, were not Immaculately Conceived by the Great Engineer, and the BUMMbuddies will hound you for months foryourheresy.

Neither of my Cyo have failed. But then I don't mount them upside down, so the rain can get in, or mount them at hub level, or ride fast enough through deep puddles to splash up water into the innards through the wire entry. That lack of waterproofing is just one of the inadequate things about BUMM lamps you're not supposed to mention in polite circles...

Do you go out in the rain much?


I live in Ireland, so you'd expect the answer to be "yes". In fact, I rarely ride through more than light showers, in part because the weather forecasts are now so good, it's no problem to pick a clear hour or two for short rides. The truth is that in the last few years I've become more concerned with whether my cycling jackets are windproof than whether they're stormproof..

Andre Jute
Bring back global warming!
  #9  
Old February 22nd 18, 04:35 PM posted to rec.bicycles.tech
Jeff Liebermann
external usenet poster
 
Posts: 2,833
Default Inexpensive LUX meter from China to measure your bike lamp's output

On Wed, 21 Feb 2018 16:52:57 -0800 (PST), Andre Jute
wrote:

Even at such an attractive price, I'm not buying the meter, Jeff.


I consider it beneficial if those recommending a product would also
have some experience using it.

For health reasons, I no longer go for those middle watches of
the night rides, as no one will go with me and it's stupid for
me to ride alone on totally empty lanes. So I have nothing
to measure for.


I have a similar problem. I don't ride at night. Too dangerous
around here and my night vision is slowly deteriorating. However,
this has not stopped me from commenting on the topic and testing
various lights.

In any event, by subjective measurement a la Roger's post,
I judge I already have what on balance I consider BUMM's best
lamp, the first series Cyo R (I also have reflectorless
version but it isn't as good in lanes as the R, and I have
the Fly-E with supposedly the same optics but with a very
nasty hotspot), so I'm not even in the market for new lamps.


Et tu Jute? I was under the delusion that we were discussing
instruments and methods of measuring light output and not a review of
available products. Oddly, every time (and I do mean every time) I
bring up the subject of light measurement, the discussion immediately
drifts away from measurements and gets mired on the mud flats of
anecdotal experience and subjective "calculation". It would seem that
the participants greatly fear making measurements and the assignment
of numbers to their favored bicycle headlight, as if this would
somehow diminish the value of their illuminating experience. I wonder
if it is even possible to discuss light measurements without the
apparently incurable product endorsements, which incidentally is only
slightly less prevalent in the flashlight forums.

Andre Jute
It's a dull life if you can't even think of a tool you want


I only need one tool. Anything within reach can be used as a hammer.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #10  
Old February 22nd 18, 11:09 PM posted to rec.bicycles.tech
Andre Jute[_2_]
external usenet poster
 
Posts: 8,705
Default Inexpensive LUX meter from China to measure your bike lamp's output

On Thursday, February 22, 2018 at 4:35:07 PM UTC, Jeff Liebermann wrote:
On Wed, 21 Feb 2018 16:52:57 -0800 (PST), Andre Jute
wrote:

Even at such an attractive price, I'm not buying the meter, Jeff.


I consider it beneficial if those recommending a product would also
have some experience using it.


See my original post at the top of the thread, where I say, "No recommendation".

For health reasons, I no longer go for those middle watches of
the night rides, as no one will go with me and it's stupid for
me to ride alone on totally empty lanes. So I have nothing
to measure for.


I have a similar problem. I don't ride at night. Too dangerous
around here and my night vision is slowly deteriorating. However,
this has not stopped me from commenting on the topic and testing
various lights.

In any event, by subjective measurement a la Roger's post,
I judge I already have what on balance I consider BUMM's best
lamp, the first series Cyo R (I also have reflectorless
version but it isn't as good in lanes as the R, and I have
the Fly-E with supposedly the same optics but with a very
nasty hotspot), so I'm not even in the market for new lamps.


Et tu Jute? I was under the delusion


I don't know any engineers with enough imagination to suffer delusions. They stop at misapprehensions. If you want to see delusions in action on a mass scale, check the so-called "resistance" in your backyard. The difference is that a misapprehension can be corrected, but a delusion is a pathology that can at best be ameliorated.

that we were discussing
instruments and methods of measuring light output and not a review of
available products. Oddly, every time (and I do mean every time) I
bring up the subject of light measurement, the discussion immediately
drifts away from measurements and gets mired on the mud flats of
anecdotal experience and subjective "calculation". It would seem that
the participants greatly fear making measurements and the assignment
of numbers to their favored bicycle headlight, as if this would
somehow diminish the value of their illuminating experience. I wonder
if it is even possible to discuss light measurements without the
apparently incurable product endorsements, which incidentally is only
slightly less prevalent in the flashlight forums.


Oh, I don't back away from abstractions where relevant. But, on a "tech" conference with a predominantly American membership, what do you expect? Thoughtful hotrodders? Pull the other one.

I only need one tool. Anything within reach can be used as a hammer.


You and Clarkson both. I'm an intellectual: as a reflex, I reach for my trusty Pickett pocket slide rule. The saddle-leather slipcase is worn almost yellow, but I feel naked without it, and they don't make them like that any more, though my favorite everyday watch, which is decades younger, has a perfectly good rotary slide rule on its bezels as a backup:
http://coolmainpress.com/andrejutewatches.html#Navihawk

Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


Andre Jute
God bless the instrument makers
 




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