Hi all,

This "could/might be" a potential seismic sensing very short period or strong motion
vertical sensor conversion item.  Originally, its a "shake table actuator".  The seller states
outright that this is NOT a seismometer.  The ~5 kilogram mass has both a piezo sensor and
a LDVT (linear differential variable transformer).  The mass ( presumed to be either iron or
a magnet?) is driven like a speaker voice coil windings around the outside of the mass. 
Seven inch diameter by one foot high item....but unknown total weight.  The bell shaped 
exterior item picture, makes it look very sturdy and solid as is.  On the other hand....the item
could be worthless as is, or in any conversion attempt.   Its (?) possible, that the metal shell
alone might be worth the cost for any other derived seismometer enclosure scheme.

In ways....I wonder if the piezo and LDVT were "somehow" mechanically disconnected, that
the original wire coil power driven input; could then be a functional magnetic induction output
velocity signal source....or....as a feedback or dampening medium?  Of course, either the 
piezo or LDVT could be entertained also,..... but their mechanical coupling might be a 
motion sensing hinderance.  

The seller is offering a quanity of ~5 "buy it now" ($74.67), and seven other starting bid 
($64.67) items.  See E-Bay item #'s, 2596230058 and 3865011737, for a picture and more info. 






Hi all,
 
This "could/might be" a potential seismic sensing very short period or strong motion
vertical sensor conversion item.  Originally, its a "shake table actuator".  The seller states
outright that this is NOT a seismometer.  The ~5 kilogram mass has both a piezo sensor and
a LDVT (linear differential variable transformer).  The mass ( presumed to be either iron or
a magnet?) is driven like a speaker voice coil windings around the outside of the mass. 
Seven inch diameter by one foot high item....but unknown total weight.  The bell shaped 
exterior item picture, makes it look very sturdy and solid as is.  On the other hand....the item
could be worthless as is, or in any conversion attempt.   Its (?) possible, that the metal shell
alone might be worth the cost for any other derived seismometer enclosure scheme.
 
In ways....I wonder if the piezo and LDVT were "somehow" mechanically disconnected, that
the original wire coil power driven input; could then be a functional magnetic induction output
velocity signal source....or....as a feedback or dampening medium?  Of course, either the 
piezo or LDVT could be entertained also,..... but their mechanical coupling might be a 
motion sensing hinderance.  
 
The seller is offering a quanity of ~5 "buy it now" ($74.67), and seven other starting bid 
($64.67) items.  See E-Bay item #'s, 2596230058 and 3865011737, for a picture and more info. 
 
Take care, Meredith Lamb