Thermal Technology (TTI), Santa Rosa, CA, has delivered a large Astro Group 1700 automatic vacuum/hydrogen furnace to the Argonne National Laboratory. The Argonne specification requires the furnace to operate up to 1600ÝC in a hydrogen atmosphere or vacuum. To meet these goals, the company supplied a model APF-1836-MS furnace system, a bell-jar type furnace with the main heating element measuring 18 in. in diameter by 36 in. high, providing a work zone 15 in. in diameter by 30 in. high. The heating element is fabricated from molybdenum sheet and provides approximately 2000 square inches of radiating surface area facing the work. Trim heaters, manufactured of molybdenum stock, are installed at each end of the work zone to insure a high degree of temperature uniformity. Fully automatic process control and unattended operation are facilitated by a Honeywell controller/programmer with a multi-loop workstation.