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We describe here the fabrication and use of a simple, low-cost salt pellet press. Our design combines two features that have been previously presented in this Journal: (i) use of a standard automotive hydraulic jack mounted on a press frame (1) and (ii) use of flat press plates and heavy cards with punched holes to produce clear pellets (2, 3). The additional contributions of this paper are (i) directions for incorporating a hydraulic pressure gauge to facilitate reproducible pellet formation, (ii) guidelines for fabricating simple stainless steel press plates, (iii) the "mass production" of sample cards for larger classes, and (iv) the use of this system for salt pellets with extended IR transmission ranges. The principal virtues of our system are low cost and ease of use. We have found it much easier and faster to get good pellets with this system than with another low-cost method using polished bolts and dies.
Press and Pressure Plate Fabrication
Figure 1 shows the essential features of the press. The 4-- ton hydraulic jack is available in auto parts stores (e.g. Lincoln Automotive, Winner Model H68027, $28). The frame consists of six 20-in. pieces of 3 X 1.5-in. angle iron (ca. $40), which can be either welded or bolted together. The only critical requirements are that the frame be tall enough to accommodate the jack, press plates, and press stop head, and that the materials be strong enough to withstand the required pressures without significant distortion. In our case, we used a frame from an older hand-turned press. The jack is fastened to a 1/2-in. steel plate with 1/4-20 bolts, and the plate in is in turn bolted to the frame. The top part of the press is another heavy plate with an attached cylindrical stop.
To add a pressure gauge, we...