PSN-L Email List Message
Subject: RE: Latest Lehman Seismometers
From: "Timothy Carpenter" geodynamics@.......
Date: Fri, 23 Apr 2010 20:14:53 -0400
Gary,
Sorry for the blunder. While looking at your site, I hit your hotlink to
Chris Chapman's site. At the top of that page is a photo entitled
"Prototype". And of course it is his prototype, not yours. So, comparing his
prototype with your Figure 1, we see that your vertical post is rotated 90
degrees from that of Chris's unit. Is there a particular reason you changed
the orientation other than to facilitate assembly?
Regards,
-Tim-
From: psn-l-request@.............. [mailto:psn-l-request@............... On
Behalf Of Gary Lindgren
Sent: Friday, April 23, 2010 7:48 PM
To: psn-l@..............
Subject: RE: Latest Lehman Seismometers
Tim,
I'm not sure what you mean by 'prototype'. The only picture I had of the
whole seismometer was Figure 1. The first unit I built 2 years ago is really
the same thing and only difference was to use 2.5" bar stock and clean
things up.
Gary
From: psn-l-request@.............. [mailto:psn-l-request@............... On
Behalf Of Timothy Carpenter
Sent: Friday, April 23, 2010 4:00 PM
To: psn-l@..............
Subject: RE: Latest Lehman Seismometers
Gary,
Very classy. I note that your prototype had its vertical bar set parallel to
the boom while the new unit has the bar perpendicular to the boom. I didn't
note anything in your commentary for the change (or did I miss it?). I
suspect that there'd be no measurable difference either way, but my first
reaction was that the bar should be orientated as in the prototype - because
of potential warping due to differential thermal distributions. But that
shouldn't really be a problem at this scale.
Regards,
-Tim-
Timothy Carpenter
5043 Whitlow Ct.
Commerce Twp., Michigan 48382
248-363-4529
248-766-1629
geodynamics@...........
geodynamics@.......
From: psn-l-request@.............. [mailto:psn-l-request@............... On
Behalf Of Gary Lindgren
Sent: Friday, April 23, 2010 5:31 PM
To: psn-l@..............
Subject: Latest Lehman Seismometers
Hello All,
I have documented the latest update to my Lehman seismometer(s). See
http://sites.google.com/site/seismicsensorinfo/lehman-seismometer
There are several pictures and also a finite-element analysis of the Chapman
magnet design.
Gary
Gary Lindgren
585 Lincoln Ave
Palo Alto CA 94301
650-326-0655
www.blue-eagle-technologies.com
Check out Lastest Seismometer Reading
cymonsplace.blogspot.com
sites.google.com/site/seismicsensorinfo/Home
Design Details
for New Vertical Seismometer
Gary,
Sorry for the blunder. =
While looking at your site, I hit your hotlink to Chris Chapman’s =
site. At the top of that page is a photo entitled =
“Prototype”. And of course it is his prototype, not yours. =
So, comparing his prototype with your Figure 1, we see that your =
vertical post is rotated 90 degrees from that of Chris’s unit. Is =
there a particular reason you changed the orientation other than to =
facilitate assembly?
Regards,
-Tim-
From:=
=
psn-l-request@.............. [mailto:psn-l-request@............... On =
Behalf Of Gary Lindgren
Sent: Friday, April 23, 2010 7:48 =
PM
To: psn-l@..............
Subject: RE: Latest =
Lehman Seismometers
Tim,
I'm not sure what you =
mean by 'prototype'. The only picture I had of the whole seismometer was =
Figure 1. The first unit I built 2 years ago is really the same thing =
and only difference was to use 2.5" bar stock and clean things =
up.
Gary
From:=
=
psn-l-request@.............. [mailto:psn-l-request@............... On =
Behalf Of Timothy Carpenter
Sent: Friday, April 23, 2010 =
4:00 PM
To: psn-l@..............
Subject: RE: Latest =
Lehman Seismometers
Gary,
Very classy. I note that =
your prototype had its vertical bar set parallel to the boom while the =
new unit has the bar perpendicular to the boom. I didn’t note =
anything in your commentary for the change (or did I miss it?). I =
suspect that there’d be no measurable difference either way, but =
my first reaction was that the bar should be orientated as in the =
prototype – because of potential warping due to differential =
thermal distributions. But that shouldn’t really be a problem at =
this scale.
Regards,
-Tim-