Vibration Dampening

I would look at Mason or Amber-Booth for spring isolators. The most benneficial course of action would be to put these spring isolators on the AHU's. I would go with at least 2" travel springs. Replace the rubber pads with the highest quality 3/4" super 'W' pad from Mason, or equal.

Thank you for the information. This will give me some direction to go.

Instead of vibration dampening you might look into vibration isolation. There is equipment available that isolates movement in one, two or all three axes of possible movement. For a small device like a microscope all it takes is the purchase of the correct type of vibration isolation table. If there are air currents moving around the area you may even need to put it in a booth.

Just search vibration isolation on GlobalSpec or google for suppliers.

Thanks very much, I appreciate it.

for what its worth, I have heard of people using a bed of dry sand to isolate vibration for various audio/video equipment. Not sure what your budget is, but I'm confident this would be one of the cheapest options. Perhaps combine with your current rubber pads? just a thought. good luck

Thanks for your suggestion it is appreciated.

I'm no expert, but I've got a couple of ideas that might work. 1) If you've got acoustical ceiling, you can get hangers cheap that clip to the metal supports, you could attach a small platform suspended from the ceiling with bungie type cord. 2) what would happen, if, in conjunction with you're rubber pads, you were to place the microscope on a piece of Styrofoam on top of a shallow pan filled with Jello, I would think that the Jello would make an excellent dampener, assuming there's a refrigerator nearby to keep it cold between uses.

In my old optical signal processing days we used giant multi-ton slabs of stone. I don't know if that will be of much help.

I remember a visit to a medical research lab when I was at school, the electron microscope on the 5th floor was sitting on its own 5 storey high column of cement and was isolated from the building completely.

The picture on the monitor shook when you stepped onto the concrete.

Try a small tub of water on a bed of soft rubber then take a large plank and cut to fit in the tub and float the unit. We did a similar project and it worked quite well.

Good answer.

A larger base ( 24" x 24" concrete, 30" x 30" concrete, 2-3" thick) will reduce the tendency of the scope to develop rocking resonance with with side loads. Depending on the type of foam rubber, four feet at the corners may be more effective than a pad under the entire mass. The resonant frequency of the whole mess can be tuned with different stiffness of foams.

Also, small solid rubber isolation mounts can work well when loaded to a higher psi loading than used for foam, and can provide more transverse isolation, because they may be softer in shear than a large piece of foam. These can, but don't always, have the advantage that they are engineered for the purpose and are available in different durometer and hysteresis values, and can be shaped to have much different stiffness in compression vs shear.

If you want to do this rigorously, you can obtain a seismic accelerometer and look at its output with a spectrum analyzer to determine the frequencies you need to isolate from. A practical solution to this problem is to use an isolation table/bench. The on-line auction houses usually have surplus units available. These are low-pass mechanical filters with a resonant frequency of less than 1 Hz. They are also available in self leveling active air powered versions.

When I was in college the pysics lab I was taking had a cheap solution for a similiar problem. We were using a laser to produce holograms. For a platform we had a large tire inner tube partially inflated with a steel slab on top. It gave a platform which allowed enough isolation to successfully shoot some small holograms. We were on the 3rd floor with airconditioning equipment operating right above us on the roof.

You can use inflated rubber post to isolate microscope from floor vibration. I multiple sensative equipment which includes Scanning electron microscope optical microscope and other highly sensative equipments and all work fine.

You may find that although the low cost effective methods including suspending the microscope from the ceiling with bungee cords, work very well, they have the downside of making the man/machine interface rather difficult. It's not convenient to use a microscope that moves every time you touch it. This is the reason the purpose made isolation tables are so convenient. The active self leveling ones even stay level when you add or remove weight to their surface. Since you haven't asked for the lowest cost solution to the problem, this is the way I would go. They are usually made from a steel or granite plate supported on soft rubber or pneumatic isolators.

Welderman,

I thank you for your input, I'm getting great suggestion to work with.

Thanks

To isolate a microscope you need to know the maximum allowable (per the microscope MFG specifications) acceleration or velocity or amplitude throughout a frequency range, say 0-125 Hz. Then you need to know what your "actual" maximum acceleration or velocity or amplitude throughout the frequency range is at your "environment"-installation. You can accurately do this with a vibration site survey, which will cost you $1000-$1500. With these two pieces of data, a vibration isolation product can be selected to meet the needs of your microscope given your environment. A Vibration Isolated Table or maybe even the smaller Vibration Isolated Table-Top Platform may work for your application. For additional information, you can contact a vibration isolation supplier like www.bilz-usa.com

Thank for the info,

Have a good week.

I finally was able to find the specialized foam rubber that I use for equalizing pressure under thin glass optical mirrors. It's called Sorbothane and I consider it to be the ideal dampening medium for your microscope if used as suggested.

http://www.sorbothane.com/material-properties.php

Good luck

L.J.