Side View of my homebrew Lehman seismometer

The base is made of welded Dexion and the two braces are made of tubular electrical conduit MIG welded to the base

Damping is a thick copper plate "eddy current" damper on the left.

Period is about 14 seconds.

Unit is shown here outside of it's protective styrofoam box made of RMAX foil-clad sytrofoam.

Shown below my recording of the Easter Island Mag 7 event that occured mid-September 96.