Hi all, We've all seen alot of the same general "swinging gate" seismometers construction method....i.e., the major pieces being the flat base plate and a mast attached to it. I suppose thats all well and good....if.....the amateur builder is lucky enough to obtain thick enough, or enough reinforcement additions to make it stable, to avoid alot of operation adjustments. This is a definite challenge to do. I've made a number of Shackleford-Gunderson seismos that more or less use a "box" frame aspect that are a different approach obviously. Admittedly with using steel and aluminum, they do take a month or more to mechanically settle down or stabilize themselves, for a more consistent operation thereafter. The main thought I bring here, is nothing more than intertaining the though of using the same approach for the more typical "swinging gate" seismometer and its base "frame" variation. For example: "If" one has a box (of whatever material), it would be likely to be more structurally stronger than the typical flat base plate and mast usually utilized by amateurs. The key here is obviously finding the strongest material again.....but....it could open alittle more options for amateur builders. With such a frame, it would be much easier to add support braces if needed. Naturally, the seismo boom/mast/mass and sensor method would have to be configured for use within such a frame. Its also possible to envision such a "frame" or "box", being possible with only 4 sides being utilized, without the top and bottom....or....the complete "box" of 6 sides, but this is dependent on the strength of the material joints, thickness. Naturally one side would have to allow access. Going further....."if" I were deprived of say, thick aluminum or other metals material, or cost limitations/budget; and the desire is there....I would "go for" whatever material I could afford....even it was a thick WOOD frame approach. Of course, I'd use a sealer/paint to give some more stability or freedom from moisture absorption. Perhaps the only other positive aspect of this approach, could be the simple addition of insulation on the inside and outside for additional thermal variation protection. This idea is not original, I'am sure, but I've yet to see any seismometer using this...outside of a "SG" type design. Perhaps others might have other limiting application objections...or have even tried this??? Meredith Lamb __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>