"Tom Potter" <tdp@earthlink.net> wrote in news:3a06dbF66l81nU1
@individual.net:

"bz" <bz+sp@ch100-5.chem.lsu.edu> wrote in message
news:Xns961B61FDC2920WQAHBGMXSZHVspammote@130.39.198.139...

"Tom Potter" <tdp@earthlink.net> wrote in news:39qr1eF65vpcaU3
@individual.net:

I am interested in analyzing surfaces of objects
to detect natural and man-made shaping of the object surface,
and I have been experimenting,
using a MP3 player/recorder to record the sound,
as I drag a "feeler" attached to the player across the objects.

I have experimented with various "transducer interface materials"
glued onto the MP3 player, and I have not found a
suitable material, as all materials have many
resonances, and those, combined with the
resonances of the MP3 players I have used,
tend to obscure the data associated with the surfaces,
that I want to analyze.

I would appreciate any input and ideas about
producing an audio signal that models a surface,
in a small portable, inexpensive package.

A small, low-power, laser probe would do a better job,
but I am hopeful of using an MP3 player/recorder for this,
as the cost, size, power consumption and frequency response
seems to be ideal.

I have a number of time series analyzer programs that
I have experimented with, but would also appreciate
any suggestions along these line.

Look up the topic of Force Microscope and Scanning tunneling Microscope.
You will find things that WORK and are being used every day to see atoms
on
surfaces.

http://physics.nist.gov/GenInt/STM/stm.html should get you started.

Are you suggesting that these devises
are small,

Yes.

portable,

relatively. They need to be attached to a mass that is suspended on
springs
in order to isolate them from vibrations traveling through the floor.

low cost,

You might be able to build one, yourself, out of a couple of old floppy
drives, and a couple of phono cartridges.

Tom Potter wrote:

"bz" <bz+sp@ch100-5.chem.lsu.edu> wrote in message
news:Xns961B61FDC2920WQAHBGMXSZHVspammote@130.39.198.139...

"Tom Potter" <tdp@earthlink.net> wrote in news:39qr1eF65vpcaU3
@individual.net:

I am interested in analyzing surfaces of objects
to detect natural and man-made shaping of the object surface,
and I have been experimenting,
using a MP3 player/recorder to record the sound,
as I drag a "feeler" attached to the player across the objects.

I have experimented with various "transducer interface materials"
glued onto the MP3 player, and I have not found a
suitable material, as all materials have many
resonances, and those, combined with the
resonances of the MP3 players I have used,
tend to obscure the data associated with the surfaces,
that I want to analyze.

I would appreciate any input and ideas about
producing an audio signal that models a surface,
in a small portable, inexpensive package.

A small, low-power, laser probe would do a better job,
but I am hopeful of using an MP3 player/recorder for this,
as the cost, size, power consumption and frequency response
seems to be ideal.

I have a number of time series analyzer programs that
I have experimented with, but would also appreciate
any suggestions along these line.

Look up the topic of Force Microscope and Scanning tunneling

Microscope.

You will find things that WORK and are being used every day to see

atoms

on
surfaces.

http://physics.nist.gov/GenInt/STM/stm.html should get you started.

Are you suggesting that these devises
are small, portable, low cost,
and provide an output that can be interpreted by a layman?

If so,
please provide a reference.

Regarding my comment about a low cost LASER probe,
does anyone have any input on how
an optical mouse might work as a surface scanner.

--
Tom Potter
http://home.earthlink.net/~tdp
http://photos.yahoo.com/tdp1001

Tom--

Recommend you post this issue on sci.electronics.repairs. Sam
Goldwasser is a leading expert in lasers and associated technology and
I'm certain will respond to general post.

It seems reasonable that one could shine a laser pointer on your
surface and let the surface dy/dx modulate the light--phonotransistor
could capture and convert to delta Voltage--which you could then
manipulate into required data. Similar to common modulated lightwave
detector.

Sci.electronics.repairs best bet--real smart guys over there also--but
little BS.

Good luck!

<cnctutwiler@wmconnect.com> wrote in message
news:1110997999.383347.313110@z14g2000cwz.googlegroups.com...

Tom--

Use a phono cartridge with O scope--dVolt ~ dy--some integration over
dt and correlation with linear distance required--but your website
suggests you can handle the politics.... sorry, I mean math. (Portable
scopes available for less than $200--but being a science guy, you
probably have one. ;-)

Good Luck--

Thanks for your input.

What I am doing now is:
------------------------
1. Gluing various materials (Silk, wool, cotton, etc.) onto an MP3 player.
2. Dragging the M3 player/material interface across the item under test.
3. Recording the sound thus created as a wave file in the MP3 player.
4. Plugging the MP3 player into a USB port and downloading the wave file to
my computer.
5. Using various time series programs, such as "Sigview" to analyze the wav
file.
Sigview provides a nice 3D picture of the data.

The main problem is that there are many resonances in the MP3 player body,
and in the material I use as an interface, that override the signals
that I want to see. I may have to take an MP3 player apart,
and isolate everything possible from the audio input.

Even then, I still need a good, resonant-free, interface material,
to "sweep the surface" with.

I welcome all input.
That addresses this application I describe.

Tom Potter wrote:

<schoenfeld1@gmail.com> wrote in message
news:1110999013.968916.186370@o13g2000cwo.googlegroups.com...

Tom Potter wrote:

I am interested in analyzing surfaces of objects
to detect natural and man-made shaping of the object surface,
and I have been experimenting,
using a MP3 player/recorder to record the sound,
as I drag a "feeler" attached to the player across the objects.

Fractal compression.

Thanks for the input.

I suspect that compression would remove
some of the data I need to analyze the surface.

What I need to do,
is get eliminate the mechanical resonances and filtering,
of the transducer and MP3 player,
so I can just work on the data associated with the
surface I am trying to analyze.


--
Tom Potter
http://home.earthlink.net/~tdp
http://photos.yahoo.com/tdp1001

Tom--

There certainly are betters ways to solve your problem--I posted the
one however that I thought had some remote possibility of being done in
your garage. I suspect if you crack the case on your MP3 it would be
like squeezing a baby bird to hard--it would never sing again.

Not being nosey--but what is the intended purpose? What measurement
standards/accuracies do you want to achieve? Micrometers 0-1" are still
only $10--Need something quick, cheap and mobile--pickup a couple of
plastic calipers for $1. They're good for accuracies to .001"

Probably not going to get alot of help from the physics boys--for a
number of reasons.