The HT-PyrOH Unit, based on truly advanced technology, is a well proven major step ahead designed for temperature up to 1500°C. The heart of the innovative neat approach of the HT-Furnace is purposely designed as Satellite Unit featuring multilevel temperature set, programmable heating rate, electronic control of direct radiation for heat transfer as well as an effective cooling rate. The HT-PyrOH includes new design for constant temperature profile in the entire hot zone to limit IRMS background.