Several points: 1)Storage: If someone will drive them to Chino, CA, I have space in my plane hangar that we could store and disassemble -- no cost and no hurry to tear the units apart. The down side is the driving/truck trip. I don't have a truck, only a small trailer towable with my car occasionally. 40 units x 150# is 6000#. The trailer is rated for a 1000# -- just a bit of overload! I'm not conversant with truck ratings, but probably the do-it-yourself truck rentals are in the ton to ton and half range. That is still shy of the requirement. It would take a tractor/trailer type to haul that 3 ton load and then you'd be back in the crating and shipping business. Such trucks require a different drivers license and are probably out of our league. Any truckers on this list that could tailgate the load? 2) A thought just occurred to me for packing for trucking if you have enclosed sides. Put down a layer of seismo units, take cans of spray foam (as used for house insulation and such) spray between the units and the sides. That would lock them in and prevent shifting. Add layers and continue in a similar manner. 2) Re: testing for noisy units. I doubt this is possible. If the noise is due to thermal fluctuations of the gas, we would not be able to get a stable enough physical (read that as a no vibration) mounting in a storage unit to get to that noise floor level. I think one just has to take their chances in this area. My guess is that the seismo units proper were evacuated and always under vacuum, then the containment vessel holding the three seismo units was back filled under pressure with helium for uniform temperature control, corrosion control and to try and keep moisture from infiltrating. Charles R. Patton __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>