Heating elements are located on top, bottom, and sides of chamber for enhanced temperature uniformity. Built-in venting system removes undesirable contaminants and moisture; extends the life span of the element and unit. The rear of the chamber incorporates a 0.38" (0.95 cm) diameter port for monitoring chamber temperatures with independent measuring devices. Optional stainless steel shelf doubles load capacity (maximum temperature of 900°C). Door safety switch protects operator by removing power to the heating elements upon opening the door. Thermocouple break protection cuts power to the heating elements, prevents a thermocouple failure runaway condition. Four temperature controllers are available: A1: Digital single set point control. A single display shows actual temperature or set point. B1: Digital single set point control with a single ramp to set point and a dwell. A single display shows actual temperature or set point. The furnaces that use this control also utilize a mechanical Over Temperature Protection relay. C1: Digital programmable control with one stored program of 8 segments. The furnaces that use this control also utilize a mechanical Over Temperature Protection relay. D1: Digital programmable control with 4 stored programs, 16 segments per program. The controller also includes RS232 communications. The furnaces that use this control also utilize a mechanical Over Temperature Protection relay. F5205-1 is supplied with cord and plug set. F5205-2 thru -3 are not supplied with a cord and plug set. 208V. Specifications: Chamber (W x H x D): 12.8" x 6.8" x 10", Chamber Capacity: 14 L, Operating Temp. (°F): 212° to 2192°, Operating Temp. (°C): 100° to 1200°, Uniformity @ 1000° C: ±2.2° C, Stability @ 1000° C: ±0.2° C, Shipping Weight: 134 Lbs.