The Picotrace digestion system is for digestion of a wide variety of geological and other materials in acid at high temperature and pressure. It consists of a Teflon-coated hot plate, a hot plate controller, and two digestion blocks which can hold a total of 32 Teflon pressure vessels. Sadly, the Picotrace company seems to have gone out of business. This material is left here for use by anyone with Picotrace systems.
Preparing samples? Here is a schematic (pdf) of the 32 sample vessels to keep track of your work (if you want to edit it, here’s an svg).