Actually, these units already have magnetic induction damping. You can see
the curved aluminum disk in the photo, and there's a strong, adjustable
magnet underneath.

 

Doug Crice

Wireless Seismic            http://www.wirelessSeismic.com

12996 Somerset Drive                phone 1-530-274-4445

Grass Valley,  CA  95945  USA    fax 1-530-274-4446

 

-----Original Message-----
From: psn-l-request@.............. [mailto:psn-l-request@............... On
Behalf Of Meredith Lamb
Sent: Thursday, December 02, 2004 10:22 PM
To: psn-l@..............
Subject: RE: Seismoscope

 

Actually...........these units are antique, and rarely used anywhere
anymore, as all they do

is put a needle (track) over a smoked glass curved surface and make of
record of a nearby

(fairly strong) quakes gyrations.  They were very well made at the time
(~late 1950's, 1960's)

 

However.........they DO present a possible IDEA route for a bi-directional
horizontal seismometer

approach.  If I remember right; they are essentially a hanging mass (S-G =
Shackleford-

Gunderson type) suspension.  It "might" be possible to derive signals with
capacitance

or displacement light sensors.  Dampening could be accomodated via magnetic
induction

eddy currents...say with the mass being copper, and magnets on the seismo
platform

adjacent nearby.  I'am not suggesting that one buy the seismoscope and
convert such;

it probably isn't worth the cost effort.

 

The basic idea is very old; but, no one has done such (S-G bi-directional
sensing) that I'am

aware of.

 

"S-G's" usually have almost nill minor tilt problems compared to other
"hanging gate" type

construction seismo's.  S-G's need a sturdy frame support
mechanism/assembly.

Obviously they are a "gravity zeroing" instrument.

 

The hanging mass "natural period" will be short in itself; but, with a
displacement sensor/s,

one should see the "L" phase (somewhat attenuated) longer quake periods
results readily. 

 

One might need a unspecified thickness of the mass hanging wire; to limit
any (air current)

mass rotation that could occur with too thin a diameter of smaller gauge
wire.   

 

Take care, Meredith Lamb

 

----- Original Message ----- 

From: Edward Ianni   

To: psn-l@..............

Sent: 12/2/2004 7:24:49 PM 

Subject: [Norton AntiSpam] Seismoscope

 

Hi Gang;

     Seismoscope on ebay.....6128658309.

Ed Ianni

















Actually, these units already have
magnetic induction damping. You can see the curved aluminum disk in the =
photo,
and there’s a strong, adjustable magnet =
underneath.

 



Doug Crice

Wireless
Seismic           =
 http://www.wirelessSeismic.com


12996 Somerset
Drive           &n=
bsp;   
phone 1-530-274-4445

Grass Valley,  CA  =
95945 
USA    fax 1-530-274-4446



 

-----Original =
Message-----

From: =
psn-l-request@..............
[mailto:psn-l-request@............... On
Behalf Of Meredith Lamb

Sent: Thursday, December =
02, 2004
10:22 PM

To: =
psn-l@..............

Subject: RE: =
Seismoscope

 



Actually...........these
units are antique, and rarely used anywhere anymore, as all they =
do





is put a needle =
(track)
over a smoked glass curved surface and make of record of a =
nearby





(fairly strong) =
quakes
gyrations.  They were very well made at the time (~late =
1950's,
1960's)





 





However.........they DO
present a possible IDEA route for a bi-directional horizontal =
seismometer





approach.  =
If I
remember right; they are essentially a hanging mass =
(S-G =3D Shackleford-





Gunderson type)
suspension.  It "might" be possible to derive signals =
with
capacitance





or displacement =
light
sensors.  Dampening could be accomodated via magnetic =
induction





eddy =
currents...say with
the mass being copper, and magnets on the seismo =
platform





adjacent =
nearby. 
I'am not suggesting that one buy the seismoscope and convert =
such;





it probably isn't =
worth
the cost effort.





 





The basic idea is =
very
old; but, no one has done such (S-G bi-directional sensing) that =
I'am





aware =
of.





 





"S-G's" =
usually
have almost nill minor tilt problems compared to other =
"hanging
gate" type





construction =
seismo's. 
S-G's need a sturdy frame support mechanism/assembly.





Obviously they =
are a
"gravity zeroing" instrument.





 





The hanging mass
"natural period" will be short in itself; but, with a =
displacement
sensor/s,





one should see =
the
"L" phase (somewhat attenuated) longer quake periods results =
readily. 





 





One might need a
unspecified thickness of the mass hanging wire; to limit any (air =
current)





mass rotation =
that could
occur with too thin a diameter of smaller gauge =
wire.   





 





Take care, =
Meredith Lamb





 





----- Original =
Message
----- 







From: Edward Ianni






To: =
psn-l@..............
=






Sent: 12/2/2004
7:24:49 PM 





Subject: [Norton
AntiSpam] Seismoscope





 





Hi Gang;





     =
Seismoscope
on ebay.....6128658309.





Ed Ianni