Bartlett-Snow indirectly heated rotary calciners can now be retrofitted with internal thermocouple assemblies to provide for material bed temperature profiling. Central tube fitted with a series of thermocouples extending into the material bed, precise ramping rates, holding periods and final product temperatures can be achieved on low through high temperature applications. Alstom Power, Inc. Air Preheater Co., Raymond Operations 4525 Weaver Parkway, Suite 250 Warrenville, IL, 60555