Roger Dodger;

Mucho Gracious.


i just cant help but think there is a very simple way
to do this that does not require a mass and spring.

Such as a strain guage and a mass, resting upon it.

No F0 to worry about.
    (Eff Zero)
Just undulations relating to changes in weight.

You set some mass on something like a bathroom scale
and amplify the output from the scale.

It seems to me that for next to nothing Manufacturing
could include general outputs for all their
various measuring devices.

Why they do not do this seems extremely selfish.

For every little improvement they want to X2 the price.

Touch a Phono Needle to the bottom of a mass on a spring
Why not get a meaningful signal.
It should work just like any velocity sensor.
Sum the outputs of a stereo cartridge.

Im sure there is nothing that i can think of
that like torture has not been tried before.

Best regards,
geoff

----- Original Message ----- 
From: "Brett Nordgren" 
To: 
Sent: Wednesday, May 12, 2010 11:26 AM
Subject: Re: Magnetic Phono Cartridge as a Seismic Velocity sensor ?


> Goeff,
> 
> An excellent reference to seismometer designs in general may be found at
> 
> http://www.reference.com/browse/Seismometer
> 
> From that page:
> " Early seismometers used optical levers or mechanical linkages to 
> amplify the small motions involved, recording on soot-covered paper 
> or photographic paper.
>   Modern instruments use electronics. "
> 
> In general obtaining adequate amplification is not a problem.  A 
> 90-cent Operational amplifier can provide all the gain you could ever 
> use.  The main problem will be obtaining a sufficiently stable, 
> low-noise, motion sensing device.
> 
> Brett
> 
> 
> At 11:31 AM 5/12/2010, you wrote:
>>Back to the light thingy,
>>Given A Mass and Spring:
>>It Seems To Me You might get
>>X1000 magnification of motion
>>by putting a light source with a small radius
>>fixed to a stationary location connected to the mass and then
>>like 50 to 100 feet more away sensing
>>the lights motion.
>>It all has to do with the fact that as the radius increases
>>so does the velocity at the perimeter.
>>And if you can bounce the light beam between two mirrors
>>It might travel 100 feet in a relatively small space.
>>It will not matter that light is only 400 to 800 angstrums ??(not 
>>sure of spelling)
>>because one nano meter at the source becomes one micro meter
>>at its destination, and, like light has no mass ??
>>
>>Have you ever seen such a mechanically amplified sensor before ?
> 
> 
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