Common specifications of the Active Pneumatic Vibration Isolation Tables

Vibration attenuators: 2nd order linear phase pneumatic filters built into the cylinders

Corner frequency of the high-cut isolators: 10 Hz

Membrane material in the cylinders: fine and durable silicone rubber

Gas supply: any kind of non-toxic, not flammable, not aggressive gas (e.g. Nitrogen, compressed air)

Pressure of the gas supply: from 1 to 2.2 Bar

The absolute pressure limit of the gas supply: 2.5 Bar

The parts of the Active Pneumatic Vibration Isolation Table

The Active Pneumatic Vibration Isolation Table has got four legs, and a top plate. The legs are assembled together with strong horizontal beams. In every legs there is a pneumatic working cylinder on the top of the leg. These working cylinders form a virtual surface, on which the top plate is floating. The actual height of the pistons in the working cylinders are controlled by pneumatic control systems built on the valve assemblies. Physically the Active Pneumatic Vibration Isolation Table has got four legs, but logically it is a table with three legs. This feature gives an excellent stability on the three base points. This trick is realised on that way that the two legs on the front have got their own control systems each. But the two legs on the rear side of the Active Pneumatic Vibration Isolation Table are internally connected parallel and controlled by only one control system. This arrangement forms a virtual middle-position leg between the two rear legs.

Attenuation diagram

You can Download the measured attenuation diagram of our vibration isolation table. In the diagram the relative attenuation is shown as a function of the frequency. During the measurements a vertical excitation was applied at the floor standing the table on. The spectral characteristics of the excitation was a white noise. The measurements were carried out in the time domain, and than they were transformed off-line to the frequency domain.

The Downloadable specification, and the complete User Manual of the Active Pneumatic Vibration Isolation Tables are available.

Active Pneumatic Vibration Isolation Tables (small size)

In our terminology the "small" size means, if the top plate is smaller than 1 m2

Size of the top plate: depends on the actual order. The smallest size is 98 x 66 cm.

Height of the top plate from the floor (small tables): 78 cm (adjustable +/- 2 cm)

Weight of the legs: 130 kg

Two models of top plates can be ordered for the small tables.

The first version of the top plate is a steel-honeycomb structure. It is covered by stainless steel surface with special magnetic feature. There are strong metric M8 holes on the top plate in a raster pattern of 100 x 100 mm.

The second version of the top plate is an Impala granite model. This is a very resistant, and smart material, but it is a very difficult procedure to make holes on the surface of the granite plate. However we accept requirements for a few holes. The specification of the fixing holes on the granite plate should be discussed before placing the order.

Weight of the top plate: 85 kg for the 98 x 66 cm model. The weight of other sizes of top plates can be calculated according to the rate of the surface.

Maximum mass load of the legs: 4 kN, including the top plate

In the pictures below a fully transparent glass top plate was used, for demonstration purpose only. Such a glass top plate is never used in real applications.

                 Click on the picture to get it in full size

Active Pneumatic Vibration Isolation Tables (big size)

In our terminology the "big" size means, if the top plate is bigger than 1 m2, but smaller than 198 x 98 cm. This 198 x 98 cm is a technological limitation, because our industrial-grade laser cutting equipment, on which the steel parts of the top plates are manufactured, can handle only these X-Y dimensions as maximum.

Height of the top plate from the floor (big tables): 78 cm + extra height. There is an addition to the height because of the higher thickness of the big (greater than 1 m2) top plates. This addition depends on the size of the top plate.

Weight of the legs: 130 kg

The top plate of the big tables is a steel-honeycomb structure. It is covered by stainless steel surface with special magnetic feature. There are strong metric M8 holes on the top plate in a raster pattern of 100 x 100 mm.

Maximum mass load of the legs: 6 kN, including the top plate

In the pictures below you can see a big table, but with an optional feature on the top plate. There is an "Optical" pattern on its top surface. This extra feature is not included in the default price.

        Click on the picture to get it in full size

Active Pneumatic Vibration Isolation Tables (huge size)

In our terminology the "huge" size means, if the top plate is greater than 198 x 98 cm. The huge tables have got modular top plates, because their top plates are divided into a few parts. These parts can not be bigger than 198 x 98 cm. This is a technological limitation, because our industrial-grade laser cutting equipment, on which the steel parts of the top plates are manufactured, can handle only these X-Y dimensions as maximum.

The maximal size of the "huge" Active Vibration Isolation Table, what we can manufacture in our workshop: with modular (divided into a few parts) top plates: 294 x 198 cm

Weight of the legs: depends on the size, and load requirements

The top plate of the huge tables is a steel-honeycomb structure. It is covered by stainless steel surface with special magnetic feature. There are strong metric M8 holes on the top plate in a raster pattern of 100 x 100 mm.

Maximum mass load of the legs: 18 kN, including the top plate

Quiet Air Compressor

There is a very popular and comfortable accessory of our Active Vibration Isolation Tables: the Quiet Air Compressor. This compressor requires no adjustment or maintenance, but it can work for decades. The Quiet Air Compressor has got its internal pressure regulator circuit optimised to supply our Vibration Isolation Tables. The working actions of the compressor make no pneumatic or mechanical disturbances for the table.

If there are no externally forced mechanical transients on the top plate of the Active Vibration Isolation Table, the compressor starts itself a few times a workday. A usual Active Vibration Isolation Table table has got such a level of air leakage what starts the Quiet Air Compressor one, or two times a day. If the Quiet Air Compressor starts itself more than five times a day, please call the repair service.

Technical data:

High pressure by default (switch off): 2.5 Bar

Low pressure by default (switch on): 1.5 Bar

Other pressure range also can be specified in the order

Internal air buffer: 3 liter

Supply voltage: 230 VAC (unfortunately 115 VAC version can not be manufactured)

Current consumption in the working periods: 1.6 A

    Click on the picture to get it in full size

Important notes:

Quiet Air Compressor is not a dangerous equipment, but you should inspect it. If you recognize, that your Quiet Air Compressor works continuously, please stop it immediately, and do not switch it on again! In such a case please call the repair service immediately! The total worktime of the motor built into the Quiet Air Compressor is 1000 hours. In normal case (when the motor starts a few times a day for a minute) the estimated lifetime of the Quiet Air Compressor is approximately 30 years. But if the motor works continuously, the 1000 hours means 41 days only! After spending the lifetime of the motor the Quiet Air Compressor can even catch fire! If the motor stops, but the voltage is applied (it is the situation when a fault appears), the current of the motor is increased dramatically, resulting a very high temperature. There is an internal thermal protector fuse, what normally breaks the current in such a case. But this fuse can also became faulty in worst case, resulting a fire in your lab, and the building!

The Quiet Air Compressor must not be tilted, because the internal lubricant oil would flow out on the tube connectors.

The starting current of the Quiet Air Compressor is approximately 12 A. It is decreased to the nominal 1.6 A in a few seconds after starting the motor, but it is necessary to connect the Quiet Air Compressor into a wall plug capable to provide 12 A of current.

"Optical" pattern, and "optical" breadboards

"Optical" pattern means: there are M6 threaded holes in 25x 25 mm pattern on the top plate. It is an optional feature of the steel-honeycomb top plates. It is useful, if many small optical elements (such as lenses, mirrors, lasers, etc.) should be positioned strongly, and precisely. The "Optical" pattern can be drilled in our workshop during the manufacturing process of the steel-polymer honeycomb structured top plates.

"Optical" breadboard means: an additional thin plate containing M6 threaded holes in 25x 25 mm pattern. This "optical" breadboard should be placed on the top plate of the Vibration Isolation Tables. It is covered by stainless steel surface with special magnetic feature.

        Click on the picture to get it in full size

Elastomeric Vibration Isolation Tables

There is a simplified vibration isolation method for such applications, which do not require high level of vibration attenuation. This method is based on specially designed elastomeric elements. These elements can be used in our standard leg system instead of the pneumatic isolators. We have developed an upgradable version, as well. The upgrade means: on-site canging of the elastomeric isolator elements to active pneumatic isolators.

Maximum mass load of the Elastomer Set (4 pieces together): 2 kN, including the top plate

Damping Plates

The Damping Plates are elastomer-based vibration isolator plates for such applications, which do not require high level of vibration attenuation. They can be put onto any given table. We manufacture the Damping Plates in two fixed sizes.

Elastomer-based Damping Plate 60 x 40 cm

    Height: 90 mm

    Mass load: 300 N

Elastomer-based Damping Plate 75 x 55 cm

    Height: 90 mm

    Mass load: 500 N