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Get a hybrid. Generally, the brakes last over 100K miles before needingOn Mon, 30 Jun 2014 13:43:17 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:
...snip...
Cars aren't bad. Diesels, in busses, trucks, and construction/farm
machinery, are.
I'm a bit skeptical about the evils of CO2, but particulates are nasty
for people and the planet.
Particulates melt snow, which is especially evil.
Cars aren't bad. What about thousands of brake linings turning to powedery
dust at a Stop sign ??
So, a far better way is to shoot a narrow beam of light down aTake a calibrated light source. Then a detector. Whatever drop there is
from the light source to the detector is the result. This is no all that
easy. What's more, I doubt you will be able to do it on a smart phone.
This requires hardware.
If you want to count particles, you need a VERY small beam spot, soUnless you use reflection, like in an optical smoke detector. Then 0%
is the baseline. He could probably count individual particles.
You might look for "aerosol charger" related to some work we didYes, it could but I have no clue how one would measure dust
accumulation using an electrometer. Besides, the forward mounts for
the insulate plate uses nylon insulators, which are hygroscopic, and
would leak badly if uses as an electrometer. Yet, there's a very low
input current op amp on the board. If some spare time finds me, I'll
investigate the patents and maybe try to reverse engineer the PCB.
You can create uniform 1 um particles with di-octylThanks for the detailed description, it
appears that this is a large project,
and would need considerable time, effort
and money. There are two aspects --
detection and measurement. The first is
straightforward -- a simple phototransistoe,
would work as a detector - like in a
smoke detector. Measurement is tough,
since then your device has to be calibrated
against a test bench. What is the test-bench ?
RobertMacy wrote:
On Mon, 30 Jun 2014 13:43:17 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:
...snip...
Cars aren't bad. Diesels, in busses, trucks, and construction/farm
machinery, are.
I'm a bit skeptical about the evils of CO2, but particulates are nasty
for people and the planet.
Particulates melt snow, which is especially evil.
Cars aren't bad. What about thousands of brake linings turning to powedery
dust at a Stop sign ??
Get a hybrid. Generally, the brakes last over 100K miles before needing
replacement. They are only used to stop the car from below 9 MPH or
so.
dakupoto@gmail.com wrote:
Thanks for the detailed description, it
appears that this is a large project,
and would need considerable time, effort
and money. There are two aspects --
detection and measurement. The first is
straightforward -- a simple phototransistoe,
would work as a detector - like in a
smoke detector. Measurement is tough,
since then your device has to be calibrated
against a test bench. What is the test-bench ?
You can create uniform 1 um particles with di-octyl
pthalate, kind of a relative of the stuff that makes
the hot butter smell at the movie theater popcorn
machine. Then, you need a particle counter, as we
have discussed. if you know particle size and the count
in some measured air sample, then you can compute the
particle density in the ambient air, by count, mass/volume
and other measures.
There are other schemes for generating known particle density.
All this should be readily searchable in the air pollution
literature from 40 years ago.
Jon
The Wiki is wrong there. Serpentine and chrysotile are two entirelyOn 7/1/2014 1:19 AM, Adrian Jansen wrote:
On 1/7/2014 8:13 AM, Phil Hobbs wrote:
The dust is pretty large compared with diesel smoke particles, so it
doesn't penetrate very far into your lungs. They got rid of the
asbestos awhile back, which was a pity. Chrysotile asbestos is nasty,
serpentine basically isn't.
Cheers
Phil Hobbs
According to my reference, its serpentine ( blue, mostly ) asbestos
which is the bad one, chrysotile ( white ) asbestos is relatively safe.
Can you quote a source for the data ?
Thanks for prodding me--looks like I was completely off track.
The Wikipedia page talks about chrysotile and serpentine being the same
thing, and amosite and crocidolite (which I'd never heard of) as the
nasty carcinogenic ones.
Of course even completely inert mineral needles will cause fibrosis if
you inhale enough of them.
Whether that's enough to justify forcing millions of drivers to use
inferior brake pads is a policy question. (Nowadays brake pads have to
warm up to achieve their maximum effect, whereas asbestos ones didn't.)
Cheers
Phil Hobbs
On Tue, 01 Jul 2014 16:18:41 -0500, Jon Elson <jmelson@wustl.edu
wrote:
RobertMacy wrote:
On Mon, 30 Jun 2014 13:43:17 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:
...snip...
Cars aren't bad. Diesels, in busses, trucks, and construction/farm
machinery, are.
I'm a bit skeptical about the evils of CO2, but particulates are nasty
for people and the planet.
Particulates melt snow, which is especially evil.
Cars aren't bad. What about thousands of brake linings turning to powedery
dust at a Stop sign ??
Get a hybrid. Generally, the brakes last over 100K miles before needing
replacement. They are only used to stop the car from below 9 MPH or
so.
No thanks. Brakes are cheap.
On 7/1/2014 8:04 PM, Adrian Jansen wrote:
On 1/7/2014 9:02 PM, Phil Hobbs wrote:
On 7/1/2014 1:19 AM, Adrian Jansen wrote:
On 1/7/2014 8:13 AM, Phil Hobbs wrote:
The dust is pretty large compared with diesel smoke particles, so it
doesn't penetrate very far into your lungs. They got rid of the
asbestos awhile back, which was a pity. Chrysotile asbestos is nasty,
serpentine basically isn't.
Cheers
Phil Hobbs
According to my reference, its serpentine ( blue, mostly ) asbestos
which is the bad one, chrysotile ( white ) asbestos is relatively safe.
Can you quote a source for the data ?
Thanks for prodding me--looks like I was completely off track.
The Wikipedia page talks about chrysotile and serpentine being the same
thing, and amosite and crocidolite (which I'd never heard of) as the
nasty carcinogenic ones.
Of course even completely inert mineral needles will cause fibrosis if
you inhale enough of them.
Whether that's enough to justify forcing millions of drivers to use
inferior brake pads is a policy question. (Nowadays brake pads have to
warm up to achieve their maximum effect, whereas asbestos ones didn't.)
Cheers
Phil Hobbs
The Wiki is wrong there. Serpentine and chrysotile are two entirely
different minerals, with different chemical composition, and biological
reactions. Just why they are both classed as "asbestos", and treated as
the same evil thing is just one of those mysteries which seems to stick
around forever.
I worked for the Consumer Product Safety Commission at the time this
regulation was being developed. At that time they were not sure just
want caused lung disease. I remember my boss was attending meetings
with EPA working on this. They seemed to feel the problem was fibers
rather than the material itself, but they didn't know just what
constituted a fiber. He said one prominent researcher defined a fiber
as anything 3 times as long as it is wide. Another researcher responded
that his car was a fiber under that definition. lol
People in this group love to criticize anyone at any time. We know a
lot more now and have the huge advantage of not being under the gun to
save lives which is exactly what they were mostly concerned with at that
time. They couldn't delay while they waited for more studies, so they
did the best they could with what they had.
If anyone feels the laws need to be reworked, then get involved and help
shape some new legislation.
I find especially ridiculous the idea that today's brake pads don't stop
the vehicles well enough. lol. I remember the junk being made in the
US in the early 70's. Today's cars are the safest we have ever driven.
On 1/7/2014 9:02 PM, Phil Hobbs wrote:
On 7/1/2014 1:19 AM, Adrian Jansen wrote:
On 1/7/2014 8:13 AM, Phil Hobbs wrote:
The dust is pretty large compared with diesel smoke particles, so it
doesn't penetrate very far into your lungs. They got rid of the
asbestos awhile back, which was a pity. Chrysotile asbestos is nasty,
serpentine basically isn't.
Cheers
Phil Hobbs
According to my reference, its serpentine ( blue, mostly ) asbestos
which is the bad one, chrysotile ( white ) asbestos is relatively safe.
Can you quote a source for the data ?
Thanks for prodding me--looks like I was completely off track.
The Wikipedia page talks about chrysotile and serpentine being the same
thing, and amosite and crocidolite (which I'd never heard of) as the
nasty carcinogenic ones.
Of course even completely inert mineral needles will cause fibrosis if
you inhale enough of them.
Whether that's enough to justify forcing millions of drivers to use
inferior brake pads is a policy question. (Nowadays brake pads have to
warm up to achieve their maximum effect, whereas asbestos ones didn't.)
Cheers
Phil Hobbs
The Wiki is wrong there. Serpentine and chrysotile are two entirely
different minerals, with different chemical composition, and biological
reactions. Just why they are both classed as "asbestos", and treated as
the same evil thing is just one of those mysteries which seems to stick
around forever.
rickman:
Today's cars are the safest we have ever driven.
Defective car keys, exploding airbags, engine controllers sensitive to RF.
batteries on fire.
Poisonous cooling substances.
The list is endless.
You are wrong.
You forgot to put that in your public directory so we cannot see it yet. I do have a better idea what you are talking about now.
You want to detect particulate matter in the air, and this is going to be optically because you just do not have many other choices.
Here is the problem, mathematically, from zero to 100 %, you must define 100 % as zero. Totaslly clean air is the setpoint, the zero, the reference. If the nibers do not start there, it will be hard to use them. It's like the audio example before, you don't say 99.7 % NOT distortion, you say 0.3 % distortion. Kinda flipped over. This is exactly the same in this case.
Take a calibrated light source. Then a detector. Whatever drop there is from the light source to the detector is the result. This is no all that easy. What's more, I doubt you will be able to do it on a smart phone. This requires hardware.
Now comes the $64 question, what kind of numbers do you want ? PPM of corbon particulates ? I would almost venture to say there is an off the shelf solution for that. In fact, what abput smoke detectors, but instead of feeding an alrm, feed it to meter or whatever. A buffer to get the levels you wanrt and then something to display the result.
If you need accuracy, then we are talking instrumentation. That is a bit harder than building a (n old style) TV set. I can do it a little bit but I am not great at it. I got a Wavetek 111 and I am not only impressed by its technology, but damn near enamoured. Fucker makes a sine wave out of a triangle at .05 % THD ! Frequency independent. Has a cool type of feedback circuit. It requies the input to be EXACLT the amplitude it expects. I just got into it like last year, but the damn thing was builtin 1 1970 !
Damn I am behind the times.
So, with your thing, I figure you should set the setpoint in a vacuum. Start with that. Whatever the output is at that point from the optical sensor then, consider that the setpoint.
Circuitry ? Well that is kinda like knowing when to use a PNP transistor instead of an NPN. It is flipped. Upside down or backwards, whatevr you want to call it.
Because of my lack of training in the field of electronics, I do not
know if the detection method, components, and overall design chosen by
this individual would be appropriate as a starting platform to achieve
the aims above.
Any input or suggestions would be greatly appreciated.
Thank you again.
-gyro
On 6/30/2014 7:57 PM, Bill Sloman wrote:
On Tuesday, 1 July 2014 06:58:53 UTC+10, jurb...@gmail.com wrote:
Another thing is the wavelength of light you use in the detector.
If you define the subject as particulate matter that is VISIBLE,
that is one thing. you could use UV or IR.
the main question here is - what results do you want ? Exactly.
http://en.wikipedia.org/wiki/Light_scattering
Rayleigh scattering is intensely wavelength dependent - to the sixth
power of the particle diameter, and inversely proportional to the
fourth power of wavelength.
It would be fun to use a bunch of light sources to measure scattering
at a number of different wavelengths, and deconvolute the results to
say something about the concentrations and sizes of the different
particles doing the scattering.
You'd need Phil Hobbs to make it work ...
Back in my mis-spent youth (or maybe early middle age) I did a lot of
particle counting work. Not exactly that kind, but particle mapping in
6 dimensions (x, y, z, radial velocity, size, and time), and
collaborated a bit with some colleagues who were doing composition
sorting for particles in fluids, using the complex refractive index of
the particle to sort out bubbles, metals, nonmetals, and carbon.
At the moment I'm doing some higher speed stuff of the same sort, but
it's kind of slow going because I don't have the mechanical design and
fabrication facilities I really need for this.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
...
Because of my lack of training in the field of electronics, I do not know if the detection method, components, and overall design chosen by this individual would be appropriate as a starting platform to achieve the aims above.
Any input or suggestions would be greatly appreciated.
Thank you again.
-gyro
Check "Dylos dc1100 pro." It is cheap and reliable.
Mass.
On Monday, June 30, 2014 9:05:28 PM UTC-4, Phil Hobbs wrote:
On 6/30/2014 7:57 PM, Bill Sloman wrote:
On Tuesday, 1 July 2014 06:58:53 UTC+10, jurb...@gmail.com wrote:
Another thing is the wavelength of light you use in the detector.
If you define the subject as particulate matter that is VISIBLE,
that is one thing. you could use UV or IR.
the main question here is - what results do you want ? Exactly.
http://en.wikipedia.org/wiki/Light_scattering
Rayleigh scattering is intensely wavelength dependent - to the sixth
power of the particle diameter, and inversely proportional to the
fourth power of wavelength.
It would be fun to use a bunch of light sources to measure scattering
at a number of different wavelengths, and deconvolute the results to
say something about the concentrations and sizes of the different
particles doing the scattering.
You'd need Phil Hobbs to make it work ...
Back in my mis-spent youth (or maybe early middle age) I did a lot of
particle counting work. Not exactly that kind, but particle mapping in
6 dimensions (x, y, z, radial velocity, size, and time), and
collaborated a bit with some colleagues who were doing composition
sorting for particles in fluids, using the complex refractive index of
the particle to sort out bubbles, metals, nonmetals, and carbon.
At the moment I'm doing some higher speed stuff of the same sort, but
it's kind of slow going because I don't have the mechanical design and
fabrication facilities I really need for this.
Phil
What kind of mechanical design facilities are you looking for?
jb
On 6/30/2014 5:22 PM, RobertMacy wrote:
On Mon, 30 Jun 2014 13:43:17 -0700, John Larkin
jlarkin@highlandtechnology.com> wrote:
...snip...
Cars aren't bad. Diesels, in busses, trucks, and construction/farm
machinery, are.
I'm a bit skeptical about the evils of CO2, but particulates are nasty
for people and the planet.
Particulates melt snow, which is especially evil.
Cars aren't bad. What about thousands of brake linings turning to
powedery dust at a Stop sign ??
The dust is pretty large compared with diesel smoke particles, so it
doesn't penetrate very far into your lungs. They got rid of the
asbestos awhile back, which was a pity. Chrysotile asbestos is nasty,
serpentine basically isn't.
Cheers
Phil Hobbs
If anyone feels the laws need to be reworked, then get involved and help
shape some new legislation.
I find especially ridiculous the idea that today's brake pads don't stop
the vehicles well enough. lol. I remember the junk being made in the
US in the early 70's. Today's cars are the safest we have ever driven.
Metal brake pads have to warm up to work properly, whereas asbestos ones
didn't. Of course, anyone who ever uses "lol" for anything might not
understand actual data.
Cheers
Phil Hobbs