Hi Chris, Jim and all other interested partys,

That was a very good summation Chris.  Perhaps, however, the
best use of a vertical is predominately for simply getting the earliest
phases of any quake/event, with the longest period (p thru s) of
roughly up to, 3-4-5 seconds.  Of course a longer period vertical
than that would likely sense those signals best.   Most verticals are
predominately used for just that aspect in realtity, which is why
the professionals pursue their use so heavily.  In the PSN amateur
related sense, and from the horizontal seismomograms presented;
one often sees the designated "p", somewhere to the left of any
obvious significant quake induced activity trace deflections....they
just CAN'T sense the vertical phase quake components.  All
of this just leads up to the "need" for a vertical of some design in the

individuals amateur seismometer setting.....perhaps to the extent
of its value over and above the use of a horizontal seismometer.

I'am dubious that a broadband vertical with all their problems
is really all that worthy of the effort involved, when it comes down
to the more practical short period phases that are actually "read";
in the general amateur (and likely the professional) realm.  On the
other hand, I don't have a broadband vertical, so, perhaps my
thought judgement isn't really totally accurate for their use.

It might just be, that any one design should incorporate the best
aspects of other previously proven function pieces and parts.
A big problem arises when it seems that some of the best use
or functional pieces/parts are in themselves fairly mechanically
complicated when addressed to a likely majority of ill-equipped
individual readers and their own capabilities for its completion.
I guess I'am always hopeful that there exists some simpler or
better way to do things, than how some of  the present designs
are laid out.

It may well be that Sean's vertical design (SM) could also be
construed in a variety of degrees (amateur/professional) of
approach; to satisfy any existing variety of potential use;
simply by utilizing the base designed mechanics for other less
sensitive sensor adoptions.  This has apparently been done
(implied in past PSN emails) in the past by others, or suggested
but I'am not aware of their success in doing so, at the moment.

Take care, Meredith

ChrisAtUpw@....... wrote:

> Hi Meredith,
>
>       Short period verticals are not too difficult to make, but they
> are of somewhat limited use. There are a number of practical /
> engineering constraints. I note that at least one design uses the U
> Alnico magnet as the seismic mass on the end of the arm. This is not a
> good idea and it will react to environmental changes in the local
> magnetic field. In the normal home, you are likely to see a very noisy
> trace. It is quite easy to damp a seismometer using readily available
> NdBFe magnets. Fluid damping is very temperature sensitive and can be
> quite messy. The much higher field supplied by NdBFe magnets can also
> be used to increase the output of coil detector systems and improve
> their range and linearity. A survey of a range of systems can be found
> at http://quake.eas.gatech.edu/Instruments/InstrumentSurvey.htm.
> Prof.Braile's link may be found by removing the seismometer reference.
>
> .................clipped.........




Hi Chris, Jim and all other interested partys,
That was a very good summation Chris.  Perhaps, however, the

best use of a vertical is predominately for simply getting the earliest

phases of any quake/event, with the longest period (p thru s) of

roughly up to, 3-4-5 seconds.  Of course a longer period vertical

than that would likely sense those signals best.   Most verticals
are

predominately used for just that aspect in realtity, which is why

the professionals pursue their use so heavily.  In the PSN amateur

related sense, and from the horizontal seismomograms presented;

one often sees the designated "p", somewhere to the left of any

obvious significant quake induced activity trace deflections....they

just CAN'T sense the vertical phase quake components.  All

of this just leads up to the "need" for a vertical of some design in
the

individuals amateur seismometer setting.....perhaps to the extent

of its value over and above the use of a horizontal seismometer.
I'am dubious that a broadband vertical with all their problems

is really all that worthy of the effort involved, when it comes down

to the more practical short period phases that are actually "read";

in the general amateur (and likely the professional) realm.  On
the

other hand, I don't have a broadband vertical, so, perhaps my

thought judgement isn't really totally accurate for their use.
It might just be, that any one design should incorporate the best

aspects of other previously proven function pieces and parts.

A big problem arises when it seems that some of the best use

or functional pieces/parts are in themselves fairly mechanically

complicated when addressed to a likely majority of ill-equipped

individual readers and their own capabilities for its completion.

I guess I'am always hopeful that there exists some simpler or

better way to do things, than how some of  the present designs

are laid out.
It may well be that Sean's vertical design (SM) could also be

construed in a variety of degrees (amateur/professional) of

approach; to satisfy any existing variety of potential use;

simply by utilizing the base designed mechanics for other less

sensitive sensor adoptions.  This has apparently been done

(implied in past PSN emails) in the past by others, or suggested

but I'am not aware of their success in doing so, at the moment.
Take care, Meredith
ChrisAtUpw@....... wrote:
Hi Meredith,
     
Short period verticals are not too difficult to make, but they are of somewhat
limited use. There are a number of practical / engineering constraints.
I note that at least one design uses the U Alnico magnet as the seismic
mass on the end of the arm. This is not a good idea and it will react to
environmental changes in the local magnetic field. In the normal home,
you are likely to see a very noisy trace. It is quite easy to damp a seismometer
using readily available NdBFe magnets. Fluid damping is very temperature
sensitive and can be quite messy. The much higher field supplied by NdBFe
magnets can also be used to increase the output of coil detector systems
and improve their range and linearity. A survey of a range of systems can
be found at http://quake.eas.gatech.edu/Instruments/InstrumentSurvey.htm.
Prof.Braile's link may be found by removing the seismometer reference.
.................clipped.........