Hi Everyone,

I received this email from Dave Youden regarding a Folded Pendulum
Seismometer design. Dave is on the PSN-L list. I've placed Dave's Lehman
photo on my system here http://www.seismicnet.com/photos/lehman1a.jpg and
his write-up here
http://www.seismicnet.com/photos/Folded_Pendulum_seismometer.doc. It's in
Microsoft Word format.

I have one question for Dave. What material was used as a base and support
for your Lehman sensor?

Regards,
Larry Cochrane
Redwood City, PSN

----- Original Message -----
From: "David H. Youden" 
To: "Larry Cochrane" 
Sent: Thursday, March 06, 2003 6:18 AM
Subject: Folded Pendulum Seismometer


> Larry,
>
> Please allow me to introduce myself.
>
> My name is Dave Youden. I am an applied research engineer employed by
> Eastman Kodak Company where I work on the design of precision production
> equipment. I am also a member of the faculty of the Mechanical and
> Aerospace Engineering Department of North Carolina State University. I
live
> in Clayton, NC, a small, but growing community Southeast of Raleigh, NC.
>
> I have had a life long interest in earth sciences, and several years ago I
> built my first seismometer (See photo Lehman.jpg). A year later I built a
> small S-G instrument the performance of which was disappointing, probably
> because the 100 mm pendulum was simply too small and was subject to
> disturbance by air currrents.
>
> As a replacement for the S-G instrument I have designed and constructed a
> folded pendulum instrument which may be of interest to members of the PSN
> group. Please take a look at the file Folded Pedulum Seismometer.doc and
if
> you think that this would be of any interest to the group, you are free to
> post it if you wish, as I do not have access to a web server.
>
> I am a member of the PSN-L mailing list, and I will be more than happy to
> answer any question that you, or anyone else may have about this
instrument.
>
> The reason that I am sending this to you is that, while web surfing the
> other day, I ran across John Lahr's web site where I saw a picture of a
> folded pendulum experiment that he has constructed. I contacted John, and
> since then have been providing information to a group of students at The
> Colorado School of Mines, who are trying to design a low-cost seismometer
> suitable for public school use. Until I contacted John I really had no
idea
> that what I have built might be of interest to anyone else.
>
> Dave...
>
> David H. Youden
> dyouden@.........
>
>


__________________________________________________________

Public Seismic Network Mailing List (PSN-L)