Thermostatically controlled coking furnace for five samples. Cast-iron block type furnace reaches the standard test temperature of 550°C (1022°F) rapidly and controls with ±1°C stability. Microprocessor temperature control has °C/°F switchable digital setpoint and display. Operator and equipment are protected by an over-temperature control circuit which automatically interrupts power to the unit should block temperature exceed the programmed cut-off point. Communications software (RS232, etc.), ramp-to-set and other enhanced features are available as extra cost options. Heavily insulated stainless steel cabinet with three-layer refractory top provides excellent heat retention.