Randy wrote:
 
I still have not answered my original question though.   I have 3  
examples from Bob's program below.  The first is similar to a spring I  
have currently set up.  The second is a zero length spring with the  same 
spring K and attachment point on the boom set to the same period.   The 
third is a softer spring of 0 length.  Given 2 springs and the same  
period, will one operate noticably better at a given period in practice? 
~~~~~~~~~~~
 
Hi Randy,
 
  The best spring to use is one of zero length. One of higher spring  
constant will have to be mounted nearer the pendulum hinge, and will exert  greater 
force on the hinge and spring mounts. It is better to have as low a  spring 
constant as possible. It should be mounted at a point on the arm where  the 
spring ends up making an angle of about 45 degrees to the arm.
 
  It is best to adjust for a period of no more than 5 seconds. Ambient  
temperature changes cause too much pendulum shift and instability at longer  
periods. The effective period can be extended by a factor of 5 or more by use of  my 
"WQFilter.exe" utility. This utility accepts and outputs PSN Type 4  files.
 
 "WQFilter.exe" is contained in "seismic_dataq.zip", which can be  downloaded 
from Web page

_http://www.jclahr.com/science/psn/mcclure/wdq_utilities/index.html_ 
(http://www.jclahr.com/science/psn/mcclure/wdq_utilities/index.html) 
 
  I urge all who operate open loop vertical sensors and Mini-Lehman  sensors 
to consider using this utility. It does wonders for me.
 
Bob
 
 





Randy wrote:
 
I still have not answered my original question though.   I ha=
ve 3=20

examples from Bob's program below.  The first is similar to a sprin=
g I=20

have currently set up.  The second is a zero length spring with the=
=20
same 
spring K and attachment point on the boom set to the same period.&n=
bsp;=20
The 
third is a softer spring of 0 length.  Given 2 springs and the=20=
same=20

period, will one operate noticably better at a given period in practice?=
=20

~~~~~~~~~~~
 
Hi Randy,
 
  The best spring to use is one of zero length. One of higher spri=
ng=20
constant will have to be mounted nearer the pendulum hinge, and will exert=20
greater force on the hinge and spring mounts. It is better to have as low a=20
spring constant as possible. It should be mounted at a point on the arm wher=
e=20
the spring ends up making an angle of about 45 degrees to the arm.
 
  It is best to adjust for a period of no more than 5 seconds. Amb=
ient=20
temperature changes cause too much pendulum shift and instability at longer=20
periods. The effective period can be extended by a factor of 5 or more by us=
e of=20
my "WQFilter.exe" utility. This utility accepts and outputs PSN Type 4=20
files.
 
 "WQFilter.exe" is contained in "seismic_dataq.zip", which can be=20
downloaded from Web page
 
  =
http://www.jclahr.com/science/psn/mcclure/wdq_utilities/index.html
 
  I urge all who operate open loop vertical sensors and Mini-Lehma=
n=20
sensors to consider using this utility. It does wonders for me.
 
Bob