A SET OF COLLETS FOR MANIPULATING THE SPECIMEN HOLDER OF THE SIEMENS ELECTRON MICROSCOPE

The modification of the Siemens electron microscope grid-holder suggested by Elbers (1) among its other advantages reduces contamination by reducing the handling of the specimen holder either with the fingers or using paper tissue or other fabrics. By using the set of collets described here such handling is entirely eliminated although the operations involved in changing the specimen may still be made easily. Figs. 1 to 10 on the facing page show the sequence of operations on extracting the holder from the microscope and dismantling for a specimen change. The specimen holder shown is the type which receives 3 mm. diameter grids. Both the collet tools are made from phosphor-bronze and terminate at each end as split collets, except for the threaded portion A (Fig. 11) which is a standard item supplied with the microscope. Use of the threaded tool as described above still allows S 6.5 CM. = FIGURE 11 The top diagram shows in greater detail the construction of operating ends A and B (see text). The bottom diagram similarly shows ends C and D.