Ultrasonic Depth Measurement in Solid Mass
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Posts: 46,084
Hello
Wanted to ping the group to see if any of you had done anything
similar to this: I have a 2 layer mass. The first layer is anywhere
from 1/8" to 1/2" and is of different composition than the sublayer.
I want to develop a stamp application that will sense the depth of
the first layer using ultrasonic wave reflection (or other means) and
return it to me.
Please let me know if you have done anything similar to this.
Thanks
Patrick
Wanted to ping the group to see if any of you had done anything
similar to this: I have a 2 layer mass. The first layer is anywhere
from 1/8" to 1/2" and is of different composition than the sublayer.
I want to develop a stamp application that will sense the depth of
the first layer using ultrasonic wave reflection (or other means) and
return it to me.
Please let me know if you have done anything similar to this.
Thanks
Patrick
Comments
sent it....----
I've never done anything like this, but it sounds like something called TDR
(time domain reflectometry) used to check cables for length
and "discontinuities". The sonar would be like the pulse send down the
cable,
the different material densities would be like the different electrical
characteristics of the different cabling materials, the interface between
the
materials would be like the aforementioned discontinuity (like a break in a
cable), and the time of the return pulse would be like the reflection from
the
original pulse. From what I understand, a lot of information can be
gathered
using TDR techniques (especially when you start analyzing the shapes and
return
times of all of the return reflections).
ofcourse, I may be totally off base here... ;-)
d...
>
Original Message
> From: pstrittmatter [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=MbgZAW5e4vF4QtUy03F-gkFc4KsQ3gTRVZMlsjUVrFMK3NVRmEqmcM4mdISNb0nsuZR4g9MrU5ksqKHpeBQCLQ]pstrittmatter@y...[/url
> Sent: Friday, May 16, 2003 8:35 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
>
>
> Hello
> Wanted to ping the group to see if any of you had done anything
> similar to this: I have a 2 layer mass. The first layer is anywhere
> from 1/8" to 1/2" and is of different composition than the sublayer.
> I want to develop a stamp application that will sense the depth of
> the first layer using ultrasonic wave reflection (or other means) and
> return it to me.
>
> Please let me know if you have done anything similar to this.
>
>
> Thanks
> Patrick
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
> Subject and Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
I used to use an ultrasonic transducer mounted in a
solid block of epoxy to find the liquid level inside
compressed cylinders. A layer of ultra sound gel
(medical) was applied to the cylinder. I think you
could hack apart a "stud finder" if you have the
capital and see if there is a signal usable back to
the stamp. I'll try to do this too (sooner or later).
Please let me know what you find out.
Regardz
--- Dave <dokagaki@w...> wrote:
> --- Sorry if this is a re-post. It got bounced back
> to me the first time I
> sent it....----
>
> I've never done anything like this, but it sounds
> like something called TDR
> (time domain reflectometry) used to check cables for
> length
> and "discontinuities". The sonar would be like the
> pulse send down the
> cable,
> the different material densities would be like the
> different electrical
> characteristics of the different cabling materials,
> the interface between
> the
> materials would be like the aforementioned
> discontinuity (like a break in a
> cable), and the time of the return pulse would be
> like the reflection from
> the
> original pulse. From what I understand, a lot of
> information can be
> gathered
> using TDR techniques (especially when you start
> analyzing the shapes and
> return
> times of all of the return reflections).
>
> ofcourse, I may be totally off base here... ;-)
>
>
> d...
>
> >
Original Message
> > From: pstrittmatter
> [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=E1nSPCkFSjH_wTYw2dUeVFV5sZMhEhKXK-EEQzVvAigDc55_egRFw5crcrZgPO47aW3wI5PnfGcXJTjDK2jr]pstrittmatter@y...[/url
> > Sent: Friday, May 16, 2003 8:35 AM
> > To: basicstamps@yahoogroups.com
> > Subject: [noparse][[/noparse]basicstamps] Ultrasonic Depth
> Measurement in Solid Mass
> >
> >
> > Hello
> > Wanted to ping the group to see if any of you had
> done anything
> > similar to this: I have a 2 layer mass. The
> first layer is anywhere
> > from 1/8" to 1/2" and is of different composition
> than the sublayer.
> > I want to develop a stamp application that will
> sense the depth of
> > the first layer using ultrasonic wave reflection
> (or other means) and
> > return it to me.
> >
> > Please let me know if you have done anything
> similar to this.
> >
> >
> > Thanks
> > Patrick
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed.
> Text in the
> > Subject and Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed.
> Text in the Subject and Body of the message will be
> ignored.
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
__________________________________
Do you Yahoo!?
The New Yahoo! Search - Faster. Easier. Bingo.
http://search.yahoo.com
it sends a EM signal into the wall (don't know how high the freq is) and
measures the response. Something about the stud finder acts like the plates
of a capacitor and the different materials under it (like drywall and studs)
form the dieletric. Ofcourse, I may be way off base on this too, so pardon
me if I'm talking through my hat...
d...
>
Original Message
> From: Bernard OConnor [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Lvw6j7zhsULg_FTqRc887z2GdAGyGy_cemwNMfRY7lV1cMkP628ry4erWnYOG9E03FoKwonPGQbNQgX9WQ]b0connor@y...[/url
> Sent: Friday, May 16, 2003 4:53 PM
> To: basicstamps@yahoogroups.com
> Subject: RE: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
>
>
> Cool project
>
> I used to use an ultrasonic transducer mounted in a
> solid block of epoxy to find the liquid level inside
> compressed cylinders. A layer of ultra sound gel
> (medical) was applied to the cylinder. I think you
> could hack apart a "stud finder" if you have the
> capital and see if there is a signal usable back to
> the stamp. I'll try to do this too (sooner or later).
> Please let me know what you find out.
>
> Regardz
>
> --- Dave <dokagaki@w...> wrote:
> > --- Sorry if this is a re-post. It got bounced back
> > to me the first time I
> > sent it....----
> >
> > I've never done anything like this, but it sounds
> > like something called TDR
> > (time domain reflectometry) used to check cables for
> > length
> > and "discontinuities". The sonar would be like the
> > pulse send down the
> > cable,
> > the different material densities would be like the
> > different electrical
> > characteristics of the different cabling materials,
> > the interface between
> > the
> > materials would be like the aforementioned
> > discontinuity (like a break in a
> > cable), and the time of the return pulse would be
> > like the reflection from
> > the
> > original pulse. From what I understand, a lot of
> > information can be
> > gathered
> > using TDR techniques (especially when you start
> > analyzing the shapes and
> > return
> > times of all of the return reflections).
> >
> > ofcourse, I may be totally off base here... ;-)
> >
> >
> > d...
> >
> > >
Original Message
> > > From: pstrittmatter
> > [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=m6FD5BM_eTjwMvD9I05pRC2bWc34z02sflA2M3aWbPsSlL5W8OWXZcIOZJI4374WDs4LeYsMfuqzXxU_EHw]pstrittmatter@y...[/url
> > > Sent: Friday, May 16, 2003 8:35 AM
> > > To: basicstamps@yahoogroups.com
> > > Subject: [noparse][[/noparse]basicstamps] Ultrasonic Depth
> > Measurement in Solid Mass
> > >
> > >
> > > Hello
> > > Wanted to ping the group to see if any of you had
> > done anything
> > > similar to this: I have a 2 layer mass. The
> > first layer is anywhere
> > > from 1/8" to 1/2" and is of different composition
> > than the sublayer.
> > > I want to develop a stamp application that will
> > sense the depth of
> > > the first layer using ultrasonic wave reflection
> > (or other means) and
> > > return it to me.
> > >
> > > Please let me know if you have done anything
> > similar to this.
> > >
> > >
> > > Thanks
> > > Patrick
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed.
> > Text in the
> > > Subject and Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed.
> > Text in the Subject and Body of the message will be
> > ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> >
> >
>
>
> __________________________________
> Do you Yahoo!?
> The New Yahoo! Search - Faster. Easier. Bingo.
> http://search.yahoo.com
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
> Subject and Body of the message will be ignored.
>
>
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>
>
assumed [noparse]:o[/noparse]) that the studfinders used the the
ultrasonic transducers to get depth. Always more than
one way around things. I'll try to get more info on
the level finders around now and get back.
Regards
--- Dave <dokagaki@w...> wrote:
> I don't think studfinders use ultrasonics. I seem
> to remember reading that
> it sends a EM signal into the wall (don't know how
> high the freq is) and
> measures the response. Something about the stud
> finder acts like the plates
> of a capacitor and the different materials under it
> (like drywall and studs)
> form the dieletric. Ofcourse, I may be way off base
> on this too, so pardon
> me if I'm talking through my hat...
>
> d...
>
> >
Original Message
> > From: Bernard OConnor [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=zeqVCdFAfQdxAI6fZKPvldsw_j8hyNwEfnYwvwxldniptC7qtLDeOIFPy1yheFyrTNwRbCMrFeMI_ghiIA]b0connor@y...[/url
> > Sent: Friday, May 16, 2003 4:53 PM
> > To: basicstamps@yahoogroups.com
> > Subject: RE: [noparse][[/noparse]basicstamps] Ultrasonic Depth
> Measurement in Solid Mass
> >
> >
> > Cool project
> >
> > I used to use an ultrasonic transducer mounted in
> a
> > solid block of epoxy to find the liquid level
> inside
> > compressed cylinders. A layer of ultra sound gel
> > (medical) was applied to the cylinder. I think you
> > could hack apart a "stud finder" if you have the
> > capital and see if there is a signal usable back
> to
> > the stamp. I'll try to do this too (sooner or
> later).
> > Please let me know what you find out.
> >
> > Regardz
> >
> > --- Dave <dokagaki@w...> wrote:
> > > --- Sorry if this is a re-post. It got bounced
> back
> > > to me the first time I
> > > sent it....----
> > >
> > > I've never done anything like this, but it
> sounds
> > > like something called TDR
> > > (time domain reflectometry) used to check cables
> for
> > > length
> > > and "discontinuities". The sonar would be like
> the
> > > pulse send down the
> > > cable,
> > > the different material densities would be like
> the
> > > different electrical
> > > characteristics of the different cabling
> materials,
> > > the interface between
> > > the
> > > materials would be like the aforementioned
> > > discontinuity (like a break in a
> > > cable), and the time of the return pulse would
> be
> > > like the reflection from
> > > the
> > > original pulse. From what I understand, a lot
> of
> > > information can be
> > > gathered
> > > using TDR techniques (especially when you start
> > > analyzing the shapes and
> > > return
> > > times of all of the return reflections).
> > >
> > > ofcourse, I may be totally off base here... ;-)
> > >
> > >
> > > d...
> > >
> > > >
Original Message
> > > > From: pstrittmatter
> > > [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=yZpE_LcTI7Ul9XoaaLng4xDOSx6qwhrIKYab5vj5Q2uMoMZxkjBEQgfcA2ZVSgoO8xJTEG-TO2OtTMg2AbFPO_vD]pstrittmatter@y...[/url
> > > > Sent: Friday, May 16, 2003 8:35 AM
> > > > To: basicstamps@yahoogroups.com
> > > > Subject: [noparse][[/noparse]basicstamps] Ultrasonic Depth
> > > Measurement in Solid Mass
> > > >
> > > >
> > > > Hello
> > > > Wanted to ping the group to see if any of you
> had
> > > done anything
> > > > similar to this: I have a 2 layer mass. The
> > > first layer is anywhere
> > > > from 1/8" to 1/2" and is of different
> composition
> > > than the sublayer.
> > > > I want to develop a stamp application that
> will
> > > sense the depth of
> > > > the first layer using ultrasonic wave
> reflection
> > > (or other means) and
> > > > return it to me.
> > > >
> > > > Please let me know if you have done anything
> > > similar to this.
> > > >
> > > >
> > > > Thanks
> > > > Patrick
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@yahoogroups.com
> > > > from the same email address that you
> subscribed.
> > > Text in the
> > > > Subject and Body of the message will be
> ignored.
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > > http://docs.yahoo.com/info/terms/
> > > >
> > > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed.
> > > Text in the Subject and Body of the message will
> be
> > > ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> > > http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > __________________________________
> > Do you Yahoo!?
> > The New Yahoo! Search - Faster. Easier. Bingo.
> > http://search.yahoo.com
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed.
> Text in the
> > Subject and Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed.
> Text in the Subject and Body of the message will be
> ignored.
>
>
> Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
>
>
__________________________________
Do you Yahoo!?
The New Yahoo! Search - Faster. Easier. Bingo.
http://search.yahoo.com
Anybody else been there? Anybody recognize the school I was in from the
place and the gear? If so, e-mail me off-line. Us thunder ducks get
lonely.), and was able after very little learning to tell exactly where the
bump in the line was from a loose or dirty co-ax connector, a kink in the
co-ax, or a broken or open end on the co-ax. But it does require a GOOD
O'Scope, and a very precise clock circuit, which will allow the return echo,
even though it is very small, to trigger the scope trace. Then it requires
that the time base of the scope be very accurately reflected in its display,
as an absolute time duration value. Ours had a vernier control that allowed
us to scroll a "blip" down the time line, superimposing it on the blip
caused by a discontinuity in the line, and then reading the time scale right
off the vernier. Obviously those TDRs were built to be TDRs. Converting, or
learning to interpret, a plain old O'Scope for this purpose might be a tough
row to hoe.
Mike
Original Message
From: Dave <dokagaki@w...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, May 16, 2003 5:53 PM
Subject: RE: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
> --- Sorry if this is a re-post. It got bounced back to me the first time
I
> sent it....----
>
> I've never done anything like this, but it sounds like something called
TDR
> (time domain reflectometry) used to check cables for length
> and "discontinuities". The sonar would be like the pulse send down the
> cable,
> the different material densities would be like the different electrical
> characteristics of the different cabling materials, the interface between
> the
> materials would be like the aforementioned discontinuity (like a break in
a
> cable), and the time of the return pulse would be like the reflection from
> the
> original pulse. From what I understand, a lot of information can be
> gathered
> using TDR techniques (especially when you start analyzing the shapes and
> return
> times of all of the return reflections).
>
> ofcourse, I may be totally off base here... ;-)
>
>
> d...
>
> >
Original Message
> > From: pstrittmatter [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=hTVr4lr8X4rlLUUFEpTX2cgRk2u6gIMVK8fIg96fAtR-Wvoj1VolEo3l0Ke2OcF3jPup4On3L6WNNMmbQ_g]pstrittmatter@y...[/url
> > Sent: Friday, May 16, 2003 8:35 AM
> > To: basicstamps@yahoogroups.com
> > Subject: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
> >
> >
> > Hello
> > Wanted to ping the group to see if any of you had done anything
> > similar to this: I have a 2 layer mass. The first layer is anywhere
> > from 1/8" to 1/2" and is of different composition than the sublayer.
> > I want to develop a stamp application that will sense the depth of
> > the first layer using ultrasonic wave reflection (or other means) and
> > return it to me.
> >
> > Please let me know if you have done anything similar to this.
> >
> >
> > Thanks
> > Patrick
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the
> > Subject and Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
and I have a useless stud finder (controls stink, works fine otherwise)
which I can do that with. GOOODDDD IDEA!
Mike
Original Message
From: Bernard OConnor <b0connor@y...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, May 16, 2003 7:52 PM
Subject: RE: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
> Cool project
>
> I used to use an ultrasonic transducer mounted in a
> solid block of epoxy to find the liquid level inside
> compressed cylinders. A layer of ultra sound gel
> (medical) was applied to the cylinder. I think you
> could hack apart a "stud finder" if you have the
> capital and see if there is a signal usable back to
> the stamp. I'll try to do this too (sooner or later).
> Please let me know what you find out.
>
> Regardz
>
> --- Dave <dokagaki@w...> wrote:
> > --- Sorry if this is a re-post. It got bounced back
> > to me the first time I
> > sent it....----
> >
> > I've never done anything like this, but it sounds
> > like something called TDR
> > (time domain reflectometry) used to check cables for
> > length
> > and "discontinuities". The sonar would be like the
> > pulse send down the
> > cable,
> > the different material densities would be like the
> > different electrical
> > characteristics of the different cabling materials,
> > the interface between
> > the
> > materials would be like the aforementioned
> > discontinuity (like a break in a
> > cable), and the time of the return pulse would be
> > like the reflection from
> > the
> > original pulse. From what I understand, a lot of
> > information can be
> > gathered
> > using TDR techniques (especially when you start
> > analyzing the shapes and
> > return
> > times of all of the return reflections).
> >
> > ofcourse, I may be totally off base here... ;-)
> >
> >
> > d...
> >
> > >
Original Message
> > > From: pstrittmatter
> > [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=psb3xUnBo9xgMFdMoodCRD2a3Qw3rgiNFGTPxb6mvnNyfXo38bi5v_AfppSx_5KiJ0MhMxFj6Blan6ILBHimZAcW]pstrittmatter@y...[/url
> > > Sent: Friday, May 16, 2003 8:35 AM
> > > To: basicstamps@yahoogroups.com
> > > Subject: [noparse][[/noparse]basicstamps] Ultrasonic Depth
> > Measurement in Solid Mass
> > >
> > >
> > > Hello
> > > Wanted to ping the group to see if any of you had
> > done anything
> > > similar to this: I have a 2 layer mass. The
> > first layer is anywhere
> > > from 1/8" to 1/2" and is of different composition
> > than the sublayer.
> > > I want to develop a stamp application that will
> > sense the depth of
> > > the first layer using ultrasonic wave reflection
> > (or other means) and
> > > return it to me.
> > >
> > > Please let me know if you have done anything
> > similar to this.
> > >
> > >
> > > Thanks
> > > Patrick
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed.
> > Text in the
> > > Subject and Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed.
> > Text in the Subject and Body of the message will be
> > ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> >
> >
>
>
> __________________________________
> Do you Yahoo!?
> The New Yahoo! Search - Faster. Easier. Bingo.
> http://search.yahoo.com
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
see if you can find some docs on it online and post a link?
Mike
Original Message
From: Dave <dokagaki@w...>
To: <basicstamps@yahoogroups.com>
Sent: Friday, May 16, 2003 8:24 PM
Subject: RE: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
> I don't think studfinders use ultrasonics. I seem to remember reading
that
> it sends a EM signal into the wall (don't know how high the freq is) and
> measures the response. Something about the stud finder acts like the
plates
> of a capacitor and the different materials under it (like drywall and
studs)
> form the dieletric. Ofcourse, I may be way off base on this too, so
pardon
> me if I'm talking through my hat...
>
> d...
>
> >
Original Message
> > From: Bernard OConnor [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=I0OXmCbbiLEYMMxYOdxxTMhdwGMiFzn111VpiXQH_DvmVuvwcXUWKUcEAJDmgGBHlbVVd0HkPV3R]b0connor@y...[/url
> > Sent: Friday, May 16, 2003 4:53 PM
> > To: basicstamps@yahoogroups.com
> > Subject: RE: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
> >
> >
> > Cool project
> >
> > I used to use an ultrasonic transducer mounted in a
> > solid block of epoxy to find the liquid level inside
> > compressed cylinders. A layer of ultra sound gel
> > (medical) was applied to the cylinder. I think you
> > could hack apart a "stud finder" if you have the
> > capital and see if there is a signal usable back to
> > the stamp. I'll try to do this too (sooner or later).
> > Please let me know what you find out.
> >
> > Regardz
> >
> > --- Dave <dokagaki@w...> wrote:
> > > --- Sorry if this is a re-post. It got bounced back
> > > to me the first time I
> > > sent it....----
> > >
> > > I've never done anything like this, but it sounds
> > > like something called TDR
> > > (time domain reflectometry) used to check cables for
> > > length
> > > and "discontinuities". The sonar would be like the
> > > pulse send down the
> > > cable,
> > > the different material densities would be like the
> > > different electrical
> > > characteristics of the different cabling materials,
> > > the interface between
> > > the
> > > materials would be like the aforementioned
> > > discontinuity (like a break in a
> > > cable), and the time of the return pulse would be
> > > like the reflection from
> > > the
> > > original pulse. From what I understand, a lot of
> > > information can be
> > > gathered
> > > using TDR techniques (especially when you start
> > > analyzing the shapes and
> > > return
> > > times of all of the return reflections).
> > >
> > > ofcourse, I may be totally off base here... ;-)
> > >
> > >
> > > d...
> > >
> > > >
Original Message
> > > > From: pstrittmatter
> > > [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=EbzwH0Ygm-GlARgzWsGqTJ9jh31GB2KggA0NcawWISjIw9hLHq1f6EolrXeCQWYOgnGF8ETW6N6ypd1-cA]pstrittmatter@y...[/url
> > > > Sent: Friday, May 16, 2003 8:35 AM
> > > > To: basicstamps@yahoogroups.com
> > > > Subject: [noparse][[/noparse]basicstamps] Ultrasonic Depth
> > > Measurement in Solid Mass
> > > >
> > > >
> > > > Hello
> > > > Wanted to ping the group to see if any of you had
> > > done anything
> > > > similar to this: I have a 2 layer mass. The
> > > first layer is anywhere
> > > > from 1/8" to 1/2" and is of different composition
> > > than the sublayer.
> > > > I want to develop a stamp application that will
> > > sense the depth of
> > > > the first layer using ultrasonic wave reflection
> > > (or other means) and
> > > > return it to me.
> > > >
> > > > Please let me know if you have done anything
> > > similar to this.
> > > >
> > > >
> > > > Thanks
> > > > Patrick
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@yahoogroups.com
> > > > from the same email address that you subscribed.
> > > Text in the
> > > > Subject and Body of the message will be ignored.
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > > http://docs.yahoo.com/info/terms/
> > > >
> > > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed.
> > > Text in the Subject and Body of the message will be
> > > ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> > > http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > __________________________________
> > Do you Yahoo!?
> > The New Yahoo! Search - Faster. Easier. Bingo.
> > http://search.yahoo.com
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the
> > Subject and Body of the message will be ignored.
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http://docs.yahoo.com/info/terms/
> >
> >
>
>
> To UNSUBSCRIBE, just send mail to:
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Body of the message will be ignored.
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>
>
>
water alarm to prevent getting hung up on sandbars. Since a sailboat leans
over under way, a depth finder transducer mounted to the transom or shooting
through the hull would be at an angle and give a false reading.
We made a swinging mount inside a piece of PVC pipe that allowed the
transducer to point straight down no matter what angle the boat was at. We
epoxied the pipe to the inside of the hull and filled it with mineral oil to
conduct the sound through the hull. Worked like a charm.
You might be able to make something similar with a rubber seal that you
could press onto the material and fill with water. This would work well for
irregular surfaces.
On the oilfield stuff we built that measured the bond between the casing,
cement and bore hole, the transmitter was a coil wound around metal core
that clicked when a large pulse was applied to the coil. The receiver was a
ceramic crystal in the shape of a cylinder that was silver plated on the
inside and outside surfaces.
The sonic signature was displayed on an oscilloscope with a camera attached.
As the tool was pulled through the pipe the camera took a photo of the scope
display.
Our favorite trick was to get a newby tech to touch both surfaces of an old
crystal that no longer worked properly, while we whacked it with a
screwdriver handle. Generally the shock they received was sufficient to make
them drop the crystal, which shattered when it hit the floor.
Original Message
> Hey, cool idea. I have been trying to find a useful ultrasonic transducer,
> and I have a useless stud finder (controls stink, works fine otherwise)
> which I can do that with. GOOODDDD IDEA!
> > I used to use an ultrasonic transducer mounted in a
> > solid block of epoxy to find the liquid level inside
> > compressed cylinders. A layer of ultra sound gel
> > (medical) was applied to the cylinder. I think you
> > could hack apart a "stud finder" if you have the
> > capital and see if there is a signal usable back to
> > the stamp. I'll try to do this too (sooner or later).
> > Please let me know what you find out.
> > > I've never done anything like this, but it sounds
> > > like something called TDR
> > > (time domain reflectometry) used to check cables for
> > > length
> > > and "discontinuities". The sonar would be like the
> > > pulse send down the
> > > cable,
> > > the different material densities would be like the
> > > different electrical
> > > characteristics of the different cabling materials,
> > > the interface between
> > > the
> > > materials would be like the aforementioned
> > > discontinuity (like a break in a
> > > cable), and the time of the return pulse would be
> > > like the reflection from
> > > the
> > > original pulse. From what I understand, a lot of
> > > information can be
> > > gathered
> > > using TDR techniques (especially when you start
> > > analyzing the shapes and
> > > return
> > > times of all of the return reflections).
> > >
> > > ofcourse, I may be totally off base here... ;-)
> > > > Wanted to ping the group to see if any of you had
> > > done anything
> > > > similar to this: I have a 2 layer mass. The
> > > first layer is anywhere
> > > > from 1/8" to 1/2" and is of different composition
> > > than the sublayer.
> > > > I want to develop a stamp application that will
> > > sense the depth of
> > > > the first layer using ultrasonic wave reflection
> > > (or other means) and
> > > > return it to me.
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1
&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=4464622.WKU.&OS=PN/4464622&RS=PN/44
64622
>
Original Message
> From: Mike Duerksen [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=MyjV5xD4-ru8oXw7tbaC3ti5i4BzulU5dwZ0ppNZEoqnpr3qbK6RWF4I6lAqsXhwX1ThjlX3HYEBALBpCiK0p2fXY2w5Mw]michael_duerksen@c...[/url
> Sent: Friday, May 16, 2003 9:07 PM
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
>
>
> I'll hack one, and let you know what I find. Meantime, someone
> else want to
> see if you can find some docs on it online and post a link?
>
> Mike
>
Original Message
> From: Dave <dokagaki@w...>
> To: <basicstamps@yahoogroups.com>
> Sent: Friday, May 16, 2003 8:24 PM
> Subject: RE: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
>
>
> > I don't think studfinders use ultrasonics. I seem to remember reading
> that
> > it sends a EM signal into the wall (don't know how high the freq is) and
> > measures the response. Something about the stud finder acts like the
> plates
> > of a capacitor and the different materials under it (like drywall and
> studs)
> > form the dieletric. Ofcourse, I may be way off base on this too, so
> pardon
> > me if I'm talking through my hat...
> >
> > d...
> >
> > >
Original Message
> > > From: Bernard OConnor [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=8okSZNxVx1fdaGzli9fog5fc_m_AW3ZNb8qFYoSI8-RngPgErT4h5NwROlZpDq7uxueh3mk_zsg]b0connor@y...[/url
> > > Sent: Friday, May 16, 2003 4:53 PM
> > > To: basicstamps@yahoogroups.com
> > > Subject: RE: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
> > >
> > >
> > > Cool project
> > >
> > > I used to use an ultrasonic transducer mounted in a
> > > solid block of epoxy to find the liquid level inside
> > > compressed cylinders. A layer of ultra sound gel
> > > (medical) was applied to the cylinder. I think you
> > > could hack apart a "stud finder" if you have the
> > > capital and see if there is a signal usable back to
> > > the stamp. I'll try to do this too (sooner or later).
> > > Please let me know what you find out.
> > >
> > > Regardz
> > >
> > > --- Dave <dokagaki@w...> wrote:
> > > > --- Sorry if this is a re-post. It got bounced back
> > > > to me the first time I
> > > > sent it....----
> > > >
> > > > I've never done anything like this, but it sounds
> > > > like something called TDR
> > > > (time domain reflectometry) used to check cables for
> > > > length
> > > > and "discontinuities". The sonar would be like the
> > > > pulse send down the
> > > > cable,
> > > > the different material densities would be like the
> > > > different electrical
> > > > characteristics of the different cabling materials,
> > > > the interface between
> > > > the
> > > > materials would be like the aforementioned
> > > > discontinuity (like a break in a
> > > > cable), and the time of the return pulse would be
> > > > like the reflection from
> > > > the
> > > > original pulse. From what I understand, a lot of
> > > > information can be
> > > > gathered
> > > > using TDR techniques (especially when you start
> > > > analyzing the shapes and
> > > > return
> > > > times of all of the return reflections).
> > > >
> > > > ofcourse, I may be totally off base here... ;-)
> > > >
> > > >
> > > > d...
> > > >
> > > > >
Original Message
> > > > > From: pstrittmatter
> > > > [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=r4-bHsfSdmATm7D7jkgraBcPGSSMT01gRoO2osDlNWD5JCgy9XgVQ0f8tiXoyek2fuBNrcO4EXchiO2hHLw]pstrittmatter@y...[/url
> > > > > Sent: Friday, May 16, 2003 8:35 AM
> > > > > To: basicstamps@yahoogroups.com
> > > > > Subject: [noparse][[/noparse]basicstamps] Ultrasonic Depth
> > > > Measurement in Solid Mass
> > > > >
> > > > >
> > > > > Hello
> > > > > Wanted to ping the group to see if any of you had
> > > > done anything
> > > > > similar to this: I have a 2 layer mass. The
> > > > first layer is anywhere
> > > > > from 1/8" to 1/2" and is of different composition
> > > > than the sublayer.
> > > > > I want to develop a stamp application that will
> > > > sense the depth of
> > > > > the first layer using ultrasonic wave reflection
> > > > (or other means) and
> > > > > return it to me.
> > > > >
> > > > > Please let me know if you have done anything
> > > > similar to this.
> > > > >
> > > > >
> > > > > Thanks
> > > > > Patrick
> > > > >
> > > > >
> > > > > To UNSUBSCRIBE, just send mail to:
> > > > > basicstamps-unsubscribe@yahoogroups.com
> > > > > from the same email address that you subscribed.
> > > > Text in the
> > > > > Subject and Body of the message will be ignored.
> > > > >
> > > > >
> > > > > Your use of Yahoo! Groups is subject to
> > > > http://docs.yahoo.com/info/terms/
> > > > >
> > > > >
> > > >
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@yahoogroups.com
> > > > from the same email address that you subscribed.
> > > > Text in the Subject and Body of the message will be
> > > > ignored.
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > > > http://docs.yahoo.com/info/terms/
> > > >
> > > >
> > >
> > >
> > > __________________________________
> > > Do you Yahoo!?
> > > The New Yahoo! Search - Faster. Easier. Bingo.
> > > http://search.yahoo.com
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the
> > > Subject and Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the
> Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> >
> >
> >
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
> Subject and Body of the message will be ignored.
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> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
a stamp/robotics newby, I hope I didn't bite off more than I could
chew.
Patrick
--- In basicstamps@yahoogroups.com, "Dave" <dokagaki@w...> wrote:
> Here's one of the relevant patents:
>
> http://patft.uspto.gov/netacgi/nph-Parser?
Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1
>
&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=4464622.WKU.&OS=PN/4464622&RS
=PN/44
> 64622
>
> >
Original Message
> > From: Mike Duerksen [noparse][[/noparse]mailto:michael_duerksen@c...]
> > Sent: Friday, May 16, 2003 9:07 PM
> > To: basicstamps@yahoogroups.com
> > Subject: Re: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid
Mass
> >
> >
> > I'll hack one, and let you know what I find. Meantime, someone
> > else want to
> > see if you can find some docs on it online and post a link?
> >
> > Mike
> >
Original Message
> > From: Dave <dokagaki@w...>
> > To: <basicstamps@yahoogroups.com>
> > Sent: Friday, May 16, 2003 8:24 PM
> > Subject: RE: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid
Mass
> >
> >
> > > I don't think studfinders use ultrasonics. I seem to remember
reading
> > that
> > > it sends a EM signal into the wall (don't know how high the
freq is) and
> > > measures the response. Something about the stud finder acts
like the
> > plates
> > > of a capacitor and the different materials under it (like
drywall and
> > studs)
> > > form the dieletric. Ofcourse, I may be way off base on this
too, so
> > pardon
> > > me if I'm talking through my hat...
> > >
> > > d...
> > >
> > > >
Original Message
> > > > From: Bernard OConnor [noparse][[/noparse]mailto:b0connor@y...]
> > > > Sent: Friday, May 16, 2003 4:53 PM
> > > > To: basicstamps@yahoogroups.com
> > > > Subject: RE: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in
Solid Mass
> > > >
> > > >
> > > > Cool project
> > > >
> > > > I used to use an ultrasonic transducer mounted in a
> > > > solid block of epoxy to find the liquid level inside
> > > > compressed cylinders. A layer of ultra sound gel
> > > > (medical) was applied to the cylinder. I think you
> > > > could hack apart a "stud finder" if you have the
> > > > capital and see if there is a signal usable back to
> > > > the stamp. I'll try to do this too (sooner or later).
> > > > Please let me know what you find out.
> > > >
> > > > Regardz
> > > >
> > > > --- Dave <dokagaki@w...> wrote:
> > > > > --- Sorry if this is a re-post. It got bounced back
> > > > > to me the first time I
> > > > > sent it....----
> > > > >
> > > > > I've never done anything like this, but it sounds
> > > > > like something called TDR
> > > > > (time domain reflectometry) used to check cables for
> > > > > length
> > > > > and "discontinuities". The sonar would be like the
> > > > > pulse send down the
> > > > > cable,
> > > > > the different material densities would be like the
> > > > > different electrical
> > > > > characteristics of the different cabling materials,
> > > > > the interface between
> > > > > the
> > > > > materials would be like the aforementioned
> > > > > discontinuity (like a break in a
> > > > > cable), and the time of the return pulse would be
> > > > > like the reflection from
> > > > > the
> > > > > original pulse. From what I understand, a lot of
> > > > > information can be
> > > > > gathered
> > > > > using TDR techniques (especially when you start
> > > > > analyzing the shapes and
> > > > > return
> > > > > times of all of the return reflections).
> > > > >
> > > > > ofcourse, I may be totally off base here... ;-)
> > > > >
> > > > >
> > > > > d...
> > > > >
> > > > > >
Original Message
> > > > > > From: pstrittmatter
> > > > > [noparse][[/noparse]mailto[noparse]:p[/noparse]strittmatter@y...]
> > > > > > Sent: Friday, May 16, 2003 8:35 AM
> > > > > > To: basicstamps@yahoogroups.com
> > > > > > Subject: [noparse][[/noparse]basicstamps] Ultrasonic Depth
> > > > > Measurement in Solid Mass
> > > > > >
> > > > > >
> > > > > > Hello
> > > > > > Wanted to ping the group to see if any of you had
> > > > > done anything
> > > > > > similar to this: I have a 2 layer mass. The
> > > > > first layer is anywhere
> > > > > > from 1/8" to 1/2" and is of different composition
> > > > > than the sublayer.
> > > > > > I want to develop a stamp application that will
> > > > > sense the depth of
> > > > > > the first layer using ultrasonic wave reflection
> > > > > (or other means) and
> > > > > > return it to me.
> > > > > >
> > > > > > Please let me know if you have done anything
> > > > > similar to this.
> > > > > >
> > > > > >
> > > > > > Thanks
> > > > > > Patrick
> > > > > >
> > > > > >
> > > > > > To UNSUBSCRIBE, just send mail to:
> > > > > > basicstamps-unsubscribe@yahoogroups.com
> > > > > > from the same email address that you subscribed.
> > > > > Text in the
> > > > > > Subject and Body of the message will be ignored.
> > > > > >
> > > > > >
> > > > > > Your use of Yahoo! Groups is subject to
> > > > > http://docs.yahoo.com/info/terms/
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > > > To UNSUBSCRIBE, just send mail to:
> > > > > basicstamps-unsubscribe@yahoogroups.com
> > > > > from the same email address that you subscribed.
> > > > > Text in the Subject and Body of the message will be
> > > > > ignored.
> > > > >
> > > > >
> > > > > Your use of Yahoo! Groups is subject to
> > > > > http://docs.yahoo.com/info/terms/
> > > > >
> > > > >
> > > >
> > > >
> > > > __________________________________
> > > > Do you Yahoo!?
> > > > The New Yahoo! Search - Faster. Easier. Bingo.
> > > > http://search.yahoo.com
> > > >
> > > > To UNSUBSCRIBE, just send mail to:
> > > > basicstamps-unsubscribe@yahoogroups.com
> > > > from the same email address that you subscribed. Text in the
> > > > Subject and Body of the message will be ignored.
> > > >
> > > >
> > > > Your use of Yahoo! Groups is subject to
> > http://docs.yahoo.com/info/terms/
> > > >
> > > >
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the
> > Subject and
> > Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
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> > >
> > >
> > >
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the
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http://docs.yahoo.com/info/terms/
> >
> >
said he saw an article in an old issue of Popular Electronics/Poptronics
that discussed building a TDR with 20 bucks in parts and a 20MHz scope. If
he finds it, I'll pass along the article reference because he said it also
had a pretty good discussion of how to interpret the results. Might help
with interpreting the sonar results. Very cool stuff. I didn't realize
that TDR was around that long.
d...
>
Original Message
> From: Mike Duerksen [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ffwne6uyH3bElUjh7r33Jl4fk5WH2X1kQJNg0lzYujlIRaB8TDG9s02kKsn-BTDWj2IWQf29vgc2uP1NfPRMzy5q]michael_duerksen@c...[/url
> Sent: Friday, May 16, 2003 9:05 PM
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
>
>
> Nope. I used TDR's in school in Pensacola, FL, in 1973 (Yeah, Corry Field.
> Anybody else been there? Anybody recognize the school I was in from the
> place and the gear? If so, e-mail me off-line. Us thunder ducks get
> lonely.), and was able after very little learning to tell exactly
> where the
> bump in the line was from a loose or dirty co-ax connector, a kink in the
> co-ax, or a broken or open end on the co-ax. But it does require a GOOD
> O'Scope, and a very precise clock circuit, which will allow the
> return echo,
> even though it is very small, to trigger the scope trace. Then it requires
> that the time base of the scope be very accurately reflected in
> its display,
> as an absolute time duration value. Ours had a vernier control
> that allowed
> us to scroll a "blip" down the time line, superimposing it on the blip
> caused by a discontinuity in the line, and then reading the time
> scale right
> off the vernier. Obviously those TDRs were built to be TDRs.
> Converting, or
> learning to interpret, a plain old O'Scope for this purpose might
> be a tough
> row to hoe.
>
> Mike
>
Original Message
> From: Dave <dokagaki@w...>
> To: <basicstamps@yahoogroups.com>
> Sent: Friday, May 16, 2003 5:53 PM
> Subject: RE: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
>
>
> > --- Sorry if this is a re-post. It got bounced back to me the
> first time
> I
> > sent it....----
> >
> > I've never done anything like this, but it sounds like something called
> TDR
> > (time domain reflectometry) used to check cables for length
> > and "discontinuities". The sonar would be like the pulse send down the
> > cable,
> > the different material densities would be like the different electrical
> > characteristics of the different cabling materials, the
> interface between
> > the
> > materials would be like the aforementioned discontinuity (like
> a break in
> a
> > cable), and the time of the return pulse would be like the
> reflection from
> > the
> > original pulse. From what I understand, a lot of information can be
> > gathered
> > using TDR techniques (especially when you start analyzing the shapes and
> > return
> > times of all of the return reflections).
> >
> > ofcourse, I may be totally off base here... ;-)
> >
> >
> > d...
> >
> > >
Original Message
> > > From: pstrittmatter [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=nt7aNcn3qxmUxUHFdm_bjsUmCY_wO5-2twDdYRiJqrsrGA7e9SXk5dwx_VV37YTyhtrMYx5t0srqYtytUA]pstrittmatter@y...[/url
> > > Sent: Friday, May 16, 2003 8:35 AM
> > > To: basicstamps@yahoogroups.com
> > > Subject: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
> > >
> > >
> > > Hello
> > > Wanted to ping the group to see if any of you had done anything
> > > similar to this: I have a 2 layer mass. The first layer is anywhere
> > > from 1/8" to 1/2" and is of different composition than the sublayer.
> > > I want to develop a stamp application that will sense the depth of
> > > the first layer using ultrasonic wave reflection (or other means) and
> > > return it to me.
> > >
> > > Please let me know if you have done anything similar to this.
> > >
> > >
> > > Thanks
> > > Patrick
> > >
> > >
> > > To UNSUBSCRIBE, just send mail to:
> > > basicstamps-unsubscribe@yahoogroups.com
> > > from the same email address that you subscribed. Text in the
> > > Subject and Body of the message will be ignored.
> > >
> > >
> > > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> > >
> > >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the
> Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> >
> >
>
>
>
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generator to determine where a cable is cut or shorted. Pretty neat stuff,
but you had to know the specs on the cable.
Original Message
> don't want to get too far off topic, but for anyone who's interested, my
dad
> said he saw an article in an old issue of Popular Electronics/Poptronics
> that discussed building a TDR with 20 bucks in parts and a 20MHz scope.
If
> he finds it, I'll pass along the article reference because he said it also
> had a pretty good discussion of how to interpret the results. Might help
> with interpreting the sonar results. Very cool stuff. I didn't realize
> that TDR was around that long.
> > Nope. I used TDR's in school in Pensacola, FL, in 1973 (Yeah, Corry
Field.
> > Anybody else been there? Anybody recognize the school I was in from the
> > place and the gear? If so, e-mail me off-line. Us thunder ducks get
> > lonely.), and was able after very little learning to tell exactly
> > where the
> > bump in the line was from a loose or dirty co-ax connector, a kink in
the
> > co-ax, or a broken or open end on the co-ax. But it does require a GOOD
> > O'Scope, and a very precise clock circuit, which will allow the
> > return echo,
> > even though it is very small, to trigger the scope trace. Then it
requires
> > that the time base of the scope be very accurately reflected in
> > its display,
> > as an absolute time duration value. Ours had a vernier control
> > that allowed
> > us to scroll a "blip" down the time line, superimposing it on the blip
> > caused by a discontinuity in the line, and then reading the time
> > scale right
> > off the vernier. Obviously those TDRs were built to be TDRs.
> > Converting, or
> > learning to interpret, a plain old O'Scope for this purpose might
> > be a tough
> > row to hoe.
signal down the cable, when the cable is terminated in its characteristic
impedance (RG-58 in a 50 ohm load, etc.) That would allow you to measure the
round trip time for a signal, which, if you divide it by two, and divide the
propagation speed in feet per second by one-half the round trip time, would
give the distance in feet that the signal traveled before reflecting off the
impedance mismatch.
Mike
Original Message
From: Rodent <daweasel@s...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, May 17, 2003 11:50 AM
Subject: Re: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
> Yeah, somewhere in one of my radio books it explains how to use a signal
> generator to determine where a cable is cut or shorted. Pretty neat stuff,
> but you had to know the specs on the cable.
>
>
Original Message
>
>
> > don't want to get too far off topic, but for anyone who's interested, my
> dad
> > said he saw an article in an old issue of Popular Electronics/Poptronics
> > that discussed building a TDR with 20 bucks in parts and a 20MHz scope.
> If
> > he finds it, I'll pass along the article reference because he said it
also
> > had a pretty good discussion of how to interpret the results. Might
help
> > with interpreting the sonar results. Very cool stuff. I didn't realize
> > that TDR was around that long.
>
> > > Nope. I used TDR's in school in Pensacola, FL, in 1973 (Yeah, Corry
> Field.
> > > Anybody else been there? Anybody recognize the school I was in from
the
> > > place and the gear? If so, e-mail me off-line. Us thunder ducks get
> > > lonely.), and was able after very little learning to tell exactly
> > > where the
> > > bump in the line was from a loose or dirty co-ax connector, a kink in
> the
> > > co-ax, or a broken or open end on the co-ax. But it does require a
GOOD
> > > O'Scope, and a very precise clock circuit, which will allow the
> > > return echo,
> > > even though it is very small, to trigger the scope trace. Then it
> requires
> > > that the time base of the scope be very accurately reflected in
> > > its display,
> > > as an absolute time duration value. Ours had a vernier control
> > > that allowed
> > > us to scroll a "blip" down the time line, superimposing it on the blip
> > > caused by a discontinuity in the line, and then reading the time
> > > scale right
> > > off the vernier. Obviously those TDRs were built to be TDRs.
> > > Converting, or
> > > learning to interpret, a plain old O'Scope for this purpose might
> > > be a tough
> > > row to hoe.
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
reflection on a material that thin would happen very fast, maybe too fast
for a stamp.
Original Message
From: Mike Duerksen [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=t2SnMLP_c-pLmvFJjYWBi9hsbV_AlfoC1qif7ihWqUgmgLz3ISu711Ysxv4xfNjzH2cwymdUt6f1JLLW0DrPNVpn]michael_duerksen@c...[/url
Sent: Saturday, May 17, 2003 4:39 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
The only cable spec you would HAVE to know is the speed of propagation of a
signal down the cable, when the cable is terminated in its characteristic
impedance (RG-58 in a 50 ohm load, etc.) That would allow you to measure the
round trip time for a signal, which, if you divide it by two, and divide the
propagation speed in feet per second by one-half the round trip time, would
give the distance in feet that the signal traveled before reflecting off the
impedance mismatch.
Mike
Original Message
From: Rodent <daweasel@s...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, May 17, 2003 11:50 AM
Subject: Re: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
> Yeah, somewhere in one of my radio books it explains how to use a signal
> generator to determine where a cable is cut or shorted. Pretty neat stuff,
> but you had to know the specs on the cable.
>
>
Original Message
>
>
> > don't want to get too far off topic, but for anyone who's interested, my
> dad
> > said he saw an article in an old issue of Popular Electronics/Poptronics
> > that discussed building a TDR with 20 bucks in parts and a 20MHz scope.
> If
> > he finds it, I'll pass along the article reference because he said it
also
> > had a pretty good discussion of how to interpret the results. Might
help
> > with interpreting the sonar results. Very cool stuff. I didn't realize
> > that TDR was around that long.
>
> > > Nope. I used TDR's in school in Pensacola, FL, in 1973 (Yeah, Corry
> Field.
> > > Anybody else been there? Anybody recognize the school I was in from
the
> > > place and the gear? If so, e-mail me off-line. Us thunder ducks get
> > > lonely.), and was able after very little learning to tell exactly
> > > where the
> > > bump in the line was from a loose or dirty co-ax connector, a kink in
> the
> > > co-ax, or a broken or open end on the co-ax. But it does require a
GOOD
> > > O'Scope, and a very precise clock circuit, which will allow the
> > > return echo,
> > > even though it is very small, to trigger the scope trace. Then it
> requires
> > > that the time base of the scope be very accurately reflected in
> > > its display,
> > > as an absolute time duration value. Ours had a vernier control
> > > that allowed
> > > us to scroll a "blip" down the time line, superimposing it on the blip
> > > caused by a discontinuity in the line, and then reading the time
> > > scale right
> > > off the vernier. Obviously those TDRs were built to be TDRs.
> > > Converting, or
> > > learning to interpret, a plain old O'Scope for this purpose might
> > > be a tough
> > > row to hoe.
>
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject and
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Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
[noparse][[/noparse]Non-text portions of this message have been removed]
to measure or if you have all day to do it. I think
that if it is in a very controlled environment you
could heat a power resistor slightly then measure how
quickly the material returns to it's original
temperature. Both the resistor and the thermistor
would have to have very good contact with the material
and precise timing cycles. Just strap it onto a
boe-bot and come back in a day.
regards
--- Sadler Porter <porter.sadler@s...> wrote:
> From the original I read 1/8 to 1/2 inch thick.
> Seems to me that any
> reflection on a material that thin would happen very
> fast, maybe too fast
> for a stamp.
>
>
>
Original Message
> From: Mike Duerksen
> [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=DbFkIwZXvkCKRo4sYT8Z_u5si5xQZl2Q5at2XK6K7AtsCywtnylzd4IoTLhMOtG-1tYWh1h6ToTpeCf7P9fB6GCtkg]michael_duerksen@c...[/url
> Sent: Saturday, May 17, 2003 4:39 PM
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] Ultrasonic Depth
> Measurement in Solid Mass
>
> The only cable spec you would HAVE to know is the
> speed of propagation of a
> signal down the cable, when the cable is terminated
> in its characteristic
> impedance (RG-58 in a 50 ohm load, etc.) That would
> allow you to measure the
> round trip time for a signal, which, if you divide
> it by two, and divide the
> propagation speed in feet per second by one-half the
> round trip time, would
> give the distance in feet that the signal traveled
> before reflecting off the
> impedance mismatch.
>
> Mike
>
Original Message
> From: Rodent <daweasel@s...>
> To: <basicstamps@yahoogroups.com>
> Sent: Saturday, May 17, 2003 11:50 AM
> Subject: Re: [noparse][[/noparse]basicstamps] Ultrasonic Depth
> Measurement in Solid Mass
>
>
> > Yeah, somewhere in one of my radio books it
> explains how to use a signal
> > generator to determine where a cable is cut or
> shorted. Pretty neat stuff,
> > but you had to know the specs on the cable.
> >
> >
Original Message
> >
> >
> > > don't want to get too far off topic, but for
> anyone who's interested, my
> > dad
> > > said he saw an article in an old issue of
> Popular Electronics/Poptronics
> > > that discussed building a TDR with 20 bucks in
> parts and a 20MHz scope.
> > If
> > > he finds it, I'll pass along the article
> reference because he said it
> also
> > > had a pretty good discussion of how to interpret
> the results. Might
> help
> > > with interpreting the sonar results. Very cool
> stuff. I didn't realize
> > > that TDR was around that long.
> >
> > > > Nope. I used TDR's in school in Pensacola, FL,
> in 1973 (Yeah, Corry
> > Field.
> > > > Anybody else been there? Anybody recognize the
> school I was in from
> the
> > > > place and the gear? If so, e-mail me off-line.
> Us thunder ducks get
> > > > lonely.), and was able after very little
> learning to tell exactly
> > > > where the
> > > > bump in the line was from a loose or dirty
> co-ax connector, a kink in
> > the
> > > > co-ax, or a broken or open end on the co-ax.
> But it does require a
> GOOD
> > > > O'Scope, and a very precise clock circuit,
> which will allow the
> > > > return echo,
> > > > even though it is very small, to trigger the
> scope trace. Then it
> > requires
> > > > that the time base of the scope be very
> accurately reflected in
> > > > its display,
> > > > as an absolute time duration value. Ours had a
> vernier control
> > > > that allowed
> > > > us to scroll a "blip" down the time line,
> superimposing it on the blip
> > > > caused by a discontinuity in the line, and
> then reading the time
> > > > scale right
> > > > off the vernier. Obviously those TDRs were
> built to be TDRs.
> > > > Converting, or
> > > > learning to interpret, a plain old O'Scope for
> this purpose might
> > > > be a tough
> > > > row to hoe.
> >
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed.
> Text in the Subject and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
> http://docs.yahoo.com/info/terms/
> >
> >
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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>
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>
>
> [noparse][[/noparse]Non-text portions of this message have been
> removed]
>
>
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would have to be the delta between the front surface reflection's time and
that for the back surface. (I think the original intent was to read material
thickness. Maybe I've lost the track) And for something even 10 inches
thick, that would still be two returns VERY close together. TDR's weren't
ever meant to measure cables that were only a few inches long. Granted that
you could get down to +-2 inch resolution, that was over a cable of 50 or
more feet. The returns for two breaks or impedance mismatches only 4 inches
apart looked like a double length "hump" on the trace. If you tried to read
a 10 inch cable (or material thickness), chances are you would only see a
trace offset up or down, depending on the way the particular TDR was
designed, and no baseline (proper impedance) section of the trace to compare
with. Not very useful for that, I'm afraid.
Mike
Original Message
From: Sadler Porter <porter.sadler@s...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, May 17, 2003 7:25 PM
Subject: RE: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
> From the original I read 1/8 to 1/2 inch thick. Seems to me that any
> reflection on a material that thin would happen very fast, maybe too fast
> for a stamp.
>
>
>
Original Message
> From: Mike Duerksen [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=Ddq4VZxjp2ouCV_FXYpowl9FLBGlxMs0IcNlZcyfzmgISY7fA-HazS18cZ2QFGhkAsS6vaRyQV76WYujieoJKcRLzA]michael_duerksen@c...[/url
> Sent: Saturday, May 17, 2003 4:39 PM
> To: basicstamps@yahoogroups.com
> Subject: Re: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
>
> The only cable spec you would HAVE to know is the speed of propagation of
a
> signal down the cable, when the cable is terminated in its characteristic
> impedance (RG-58 in a 50 ohm load, etc.) That would allow you to measure
the
> round trip time for a signal, which, if you divide it by two, and divide
the
> propagation speed in feet per second by one-half the round trip time,
would
> give the distance in feet that the signal traveled before reflecting off
the
> impedance mismatch.
>
> Mike
>
Original Message
> From: Rodent <daweasel@s...>
> To: <basicstamps@yahoogroups.com>
> Sent: Saturday, May 17, 2003 11:50 AM
> Subject: Re: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
>
>
> > Yeah, somewhere in one of my radio books it explains how to use a signal
> > generator to determine where a cable is cut or shorted. Pretty neat
stuff,
> > but you had to know the specs on the cable.
> >
> >
Original Message
> >
> >
> > > don't want to get too far off topic, but for anyone who's interested,
my
> > dad
> > > said he saw an article in an old issue of Popular
Electronics/Poptronics
> > > that discussed building a TDR with 20 bucks in parts and a 20MHz
scope.
> > If
> > > he finds it, I'll pass along the article reference because he said it
> also
> > > had a pretty good discussion of how to interpret the results. Might
> help
> > > with interpreting the sonar results. Very cool stuff. I didn't
realize
> > > that TDR was around that long.
> >
> > > > Nope. I used TDR's in school in Pensacola, FL, in 1973 (Yeah, Corry
> > Field.
> > > > Anybody else been there? Anybody recognize the school I was in from
> the
> > > > place and the gear? If so, e-mail me off-line. Us thunder ducks get
> > > > lonely.), and was able after very little learning to tell exactly
> > > > where the
> > > > bump in the line was from a loose or dirty co-ax connector, a kink
in
> > the
> > > > co-ax, or a broken or open end on the co-ax. But it does require a
> GOOD
> > > > O'Scope, and a very precise clock circuit, which will allow the
> > > > return echo,
> > > > even though it is very small, to trigger the scope trace. Then it
> > requires
> > > > that the time base of the scope be very accurately reflected in
> > > > its display,
> > > > as an absolute time duration value. Ours had a vernier control
> > > > that allowed
> > > > us to scroll a "blip" down the time line, superimposing it on the
blip
> > > > caused by a discontinuity in the line, and then reading the time
> > > > scale right
> > > > off the vernier. Obviously those TDRs were built to be TDRs.
> > > > Converting, or
> > > > learning to interpret, a plain old O'Scope for this purpose might
> > > > be a tough
> > > > row to hoe.
> >
> >
> >
> >
> > To UNSUBSCRIBE, just send mail to:
> > basicstamps-unsubscribe@yahoogroups.com
> > from the same email address that you subscribed. Text in the Subject
and
> Body of the message will be ignored.
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
>
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the Subject and
> Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
> [noparse][[/noparse]Non-text portions of this message have been removed]
>
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
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>
>
sort to read the return? A piezo element held against the material might
work.
Original Message
> Probably true. Besides, the important value in order to read the thickness
> would have to be the delta between the front surface reflection's time and
> that for the back surface. (I think the original intent was to read
material
> thickness. Maybe I've lost the track) And for something even 10 inches
> thick, that would still be two returns VERY close together. TDR's weren't
> ever meant to measure cables that were only a few inches long. Granted
that
> you could get down to +-2 inch resolution, that was over a cable of 50 or
> more feet. The returns for two breaks or impedance mismatches only 4
inches
> apart looked like a double length "hump" on the trace. If you tried to
read
> a 10 inch cable (or material thickness), chances are you would only see a
> trace offset up or down, depending on the way the particular TDR was
> designed, and no baseline (proper impedance) section of the trace to
compare
> with. Not very useful for that, I'm afraid.
> > From the original I read 1/8 to 1/2 inch thick. Seems to me that any
> > reflection on a material that thin would happen very fast, maybe too
fast
> > for a stamp.
signal processing of the echo. A friend of mine, who is a world-class
expert in an esoteric area of engineering called system identification,
holds a patent on pattern recognition of "micro squeaks" in rocks.
These rocks are in the walls of mine shafts a few miles deep, and
compression forces cause them to emit squeaks with certain frequency
characteristics. Certain squeaks can signal when structural stability
is likely to lead to a mine collapse, therefore saving the lives of the
miners.
Dennis
Original Message
From: Rodent [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=biRohuYaWbZnlPS6rITkYE9Uv3ULb6ltq4a3Uvk9IX20tK0lCFrFvE-rs4u_HIqFxKbeYG07kQfo4w]daweasel@s...[/url
Sent: Sunday, May 18, 2003 4:33 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] Ultrasonic Depth Measurement in Solid Mass
What if you modified a relay to thump the material and used a sensor of
some sort to read the return? A piezo element held against the material
might work.
Original Message
> Probably true. Besides, the important value in order to read the
> thickness would have to be the delta between the front surface
> reflection's time and that for the back surface. (I think the original
> intent was to read
material
> thickness. Maybe I've lost the track) And for something even 10 inches
> thick, that would still be two returns VERY close together. TDR's
> weren't ever meant to measure cables that were only a few inches long.
> Granted
that
> you could get down to +-2 inch resolution, that was over a cable of 50
> or more feet. The returns for two breaks or impedance mismatches only
> 4
inches
> apart looked like a double length "hump" on the trace. If you tried to
read
> a 10 inch cable (or material thickness), chances are you would only
> see a trace offset up or down, depending on the way the particular TDR
> was designed, and no baseline (proper impedance) section of the trace
> to
compare
> with. Not very useful for that, I'm afraid.
> > From the original I read 1/8 to 1/2 inch thick. Seems to me that
> > any reflection on a material that thin would happen very fast, maybe
> > too
fast
> > for a stamp.
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there more than one layer, and if so, how are the layers bonded together,
and what is the measurement for.
Original Message
> Rodent's idea might work, but also might require some sophisticated
> signal processing of the echo. A friend of mine, who is a world-class
> expert in an esoteric area of engineering called system identification,
> holds a patent on pattern recognition of "micro squeaks" in rocks.
> These rocks are in the walls of mine shafts a few miles deep, and
> compression forces cause them to emit squeaks with certain frequency
> characteristics. Certain squeaks can signal when structural stability
> is likely to lead to a mine collapse, therefore saving the lives of the
> miners.
>
Original Message
> What if you modified a relay to thump the material and used a sensor of
> some sort to read the return? A piezo element held against the material
> might work.
>
>
Original Message
>
>
> > Probably true. Besides, the important value in order to read the
> > thickness would have to be the delta between the front surface
> > reflection's time and that for the back surface. (I think the original
>
> > intent was to read
> material
> > thickness. Maybe I've lost the track) And for something even 10 inches
>
> > thick, that would still be two returns VERY close together. TDR's
> > weren't ever meant to measure cables that were only a few inches long.
>
> > Granted
> that
> > you could get down to +-2 inch resolution, that was over a cable of 50
>
> > or more feet. The returns for two breaks or impedance mismatches only
> > 4
> inches
> > apart looked like a double length "hump" on the trace. If you tried to
> read
> > a 10 inch cable (or material thickness), chances are you would only
> > see a trace offset up or down, depending on the way the particular TDR
>
> > was designed, and no baseline (proper impedance) section of the trace
> > to
> compare
> > with. Not very useful for that, I'm afraid.
>
> > > From the original I read 1/8 to 1/2 inch thick. Seems to me that
> > > any reflection on a material that thin would happen very fast, maybe
>
> > > too
> fast
> > > for a stamp.