Vacuum compatible table tops are now almost a commonplace requirement. We have developed a broad selection of materials and construction techniques that are consistent with good vacuum practice down to less than 10-7 torr. Our results, from these investigations, include measured data on outgassing rates for actual completed structures. Custom versions of Newport tables and breadboards have been certified for airborne and space applications.
Both nonferromagnetic and nonconductive materials can be substituted in the construction of Newport tables and breadboards. Aside from the more usual nonferromagnetic metals, other potential alternatives include graphite epoxy, fiberglass, ceramics, and some of the exotic new composite materials.
Cleanroom machinery applications sometimes require that laminar airflow or a vacuum be pulled through an optical table, breadboard or honeycomb equipment pedestal. Newport offers a perforated honeycomb core design to allow air to move through and between individual honeycomb cells. Used with a non-sealed grid hole top, full laminar airflow can be achieved through the honeycomb structure. Pipe couplings can be installed into the top, side or bottom of the structure to allow connection of negative pressure air handling systems.
Connecting together smaller panels is usually the best way to produce large, irregularly shaped structures. Tables can be joined together in a variety of configurations including: "T"-shapes; "L"-shapes; angles, and multiple levels. The connections can be either permanent or detachable. Detachable sections make for easier transportability and permit on-site reassembly past doorways or other obstructions.
Doubler interfaces are described in the section on modular tables. They are the preferred attachment between table sections because the resultant table exhibits virtually no compromises in performance as compared to a monolithic structure. Doubler interfaces are effective in transferring stresses across regions where there are discontinuities in skin planes and they are, therefore, the recommended attachment for panels with differing thicknesses.
Flanged interfaces are generally used where two panels are joined with their planes at right angles, i.e. with the end or side of one attached to the surface of the other.
This type of joint requires the greatest amount of internal reinforcement, particularly for the table which has the flange attached to its surface.