In a message dated 07/02/2006, jonfr500@......... writes:

Is the  Shackleford-Gundersen Seismometer long period seismometer or
short period  seismometer. I was looking at the info on the psn page
regarding this  seismometer.


Hi Jon,
 
    It is a long period seismometer with a second  channel high frequency 
output. You start with a vertical pendulum of maybe 1 sec  period and extend the 
period using a linear distance transducer and electronic  force feedback. See 
_http://psn.quake.net/freqtest.html_ (http://psn.quake.net/freqtest.html)  
Being  a vertical pendulum, it does not have the precision tilt setup 
requirements of a  Lehman. It is also physically smaller.
 
    Regards,
 
    Chris Chapman






In a message dated 07/02/2006, jonfr500@......... writes:
<=
FONT=20
  style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size=
=3D2>Is the=20
  Shackleford-Gundersen Seismometer long period seismometer or
short peri=
od=20
  seismometer. I was looking at the info on the psn page
regarding this=20
  seismometer.

Hi Jon,
 
    It is a long period seismometer with a second=20
channel high frequency output. You start with a vertical pendulum of maybe 1=
 sec=20
period and extend the period using a linear distance transducer and electron=
ic=20
force feedback. See http://psn.quake.net/freqtest.ht=
ml Being=20
a vertical pendulum, it does not have the precision tilt setup requirements=20=
of a=20
Lehman. It is also physically smaller.
 
    Regards,
 
    Chris Chapman