Hi All,  I finished the Folded Pendulum Sensor.  I will send pictures to =
anyone interested.  After I test it, and if it works, I will then post =
the pictures on the internet, like I did on the "Slinky"

All in all, it was a bit of a bear.   I guess the fact it was a new =
concept, for me, and that I could find only a couple examples, was part =
of the issue.   Thanks to all who helped me, or I would have never =
gotten this far.   At this point it seems to be working, but I can =
qualify it's performance after it is tested.

The two pendulum, one normal, one inverted have the same length, 7.625", =
 The box it is contained in is 32"x24".
The best working natural period I could measure, was about 6 to 10 =
seconds.  I could obtain 15 seconds but it was too unstable.
It has been pointed out to me that I should have achieved a longer =
period using this approach.   Perhaps other articles and examples may =
show me how to improve the design.

By the way if and when I record earthquakes using the sensor I will post =
them on PSN as TCIDF, for "Folded Pendulum"
TCIDzs=3D "Slinky is setting in the corner.

I do have a question about measuring a sensor's period.  I assume the =
best way is to remove the damper, tap the arm, and time the cycles.

Q.   Is there another way, to estimate its period, with the damper =
installed?   On this sensor the damper is difficult to remove.
=20

Different Subject

Q.   I don't really understand the FFT in AmaSeis.   If I take one hour =
of trace, containing road construction noise, and use Control/Fourier =
Transform/Linear,   I see a large spike at 1.607Hz another at 2.597Hz =
and some other signals.
Is this the frequency of the noise?

Q.  I highlighted an earthquake, and using the same steps I see a =
section of spikes, starting at .2 and ending at .8Hz
Is that the frequency of the recorded earthquake?

Thanks Again,  Ted







Hi All,  I finished the Folded =
Pendulum=20
Sensor.  I will send pictures to anyone interested.  After I =
test it,=20
and if it works, I will then post the pictures on the internet, like I =
did on=20
the "Slinky"
 
All in all, it was a bit of a =
bear.   I=20
guess the fact it was a new concept, for me, and that I could find =
only a=20
couple examples, was part of the issue.   Thanks to all who =
helped me,=20
or I would have never gotten this far.   At this point it =
seems to be=20
working, but I can qualify it's performance after it is =
tested.
 
The two pendulum, one normal, one =
inverted have the=20
same length, 7.625",  The box it is contained in is =
32"x24".
The best working natural period I could =

measure, was about 6 to 10 seconds.  I could obtain 15 seconds =
but it=20
was too unstable.
It has been pointed out to me that I =
should have=20
achieved a longer period using this approach.   Perhaps other =
articles=20
and examples may show me how to improve the design.
 
By the way if and when I record =
earthquakes using=20
the sensor I will post them on PSN as TCIDF, for "Folded =
Pendulum"
TCIDzs=3D "Slinky is setting in the=20
corner.
 
I do have a question about measuring a =
sensor's=20
period.  I assume the best way is to remove the damper, tap the =
arm, and=20
time the cycles.
 
Q.   Is there another way, to =
estimate=20
its period, with the damper installed?   On this sensor the =
damper is=20
difficult to remove.
 
 
Different Subject
 
Q.   I don't really =
understand the FFT in=20
AmaSeis.   If I take one hour of trace, containing road =
construction=20
noise, and use Control/Fourier Transform/Linear,   I see a =
large spike=20
at 1.607Hz another at 2.597Hz and some other signals.
Is this the frequency of the =
noise?
 
Q.  I highlighted an earthquake, =
and using the=20
same steps I see a section of spikes, starting at .2 and ending at=20
..8Hz
Is that the frequency of the recorded=20
earthquake?
 
Thanks Again,  Ted