Abstract: A system is described for precise monitoring and control of the carbon content of the atmosphere of a furnace such as a carburizer used in the heat-processing of steel parts. The disclosed apparatus includes a sampling system for withdrawing a gas sample from the atmosphere within a furnace and an analyzer for producing signals indicative of the partial pressures of at least two gaseous components such as carbon dioxide and carbon monoxide. The analyzer preferably utilizes selective absorption of narrow-band infrared radiation signals in determining these signals. A processor combines the signals indicative of partial pressures with parameters obtained from measurements of furnace temperature, and calculates carbon potential of the furnace atmosphere. The processor output is coupled with an atmosphere control which maintains desired levels of carbon potential in the atmosphere of the furnace by, for example, regulating the flow of an enriching gas to the furnace.

Abstract: A method and apparatus are disclosed for heat-treating parts in a furnace system which uses a minimum total amount of energy. The self-contained, continuous heat-treating system includes components such as a carburizer, a tempering furnace, and a part cooler. Energy transfer between these and other components operable at different temperatures and/or energy requirements are used to maximize thermal efficiency of the system.