Sample exchange system

A sample exchange system for transferring a sample between two environments, said exchange system comprising:

• a circular platen having means for supporting the sample, said platen having at least six wedge shaped ramps in its periphery;
• a transfer fork located in a first environment, said fork having a first and a second surface and a shaft on a central axis extending from its second surface, said fork being moveable along and rotatable about said axis, said fork having three equally spaced spring fingers extending from said first surface for entering a first three of said ramps in said platen and for grasping said platen upon a small rotation of said platen in a second direction;
• a sample dock located in a second environment, said dock being axially aligned with said transfer fork for receiving said platen from said fork, said dock having three equally spaced fingers for entering the second three of said ramps in said platen and for grasping said platen upon rotation of said platen by said fork in a first direction whereby said platen is released from said transfer fork;
• wherin said circular platen includes a first circular disc having said first three of said ramps in its periphery for coupling to the fingers of said transfer fork, and a second disc coaxial with and spaced from said first disc and having said second of said ramps foor coupling to the said sample dock;
• and wherein said first circular disc is electrically insulated from said second disc and said first circular disc is divided into two semicircular sectors, said semicircular sectors being spaced from each other.