Automatic control furnaces have single set point, proportional temperature control. Furnaces include an analog temperature indicator with 50°C/F increments. Furnaces feature fiber insulation in the chamber and firebrick insulation around the heating elements. The fiber insulation cools down fast while the firebrick provides the heating elements with a longer life. Heating elements are easily replaceable- just disconnect and slide out. A safety interlock switch disconnects power when the door is open. Vertical lift door has maximum access with minimum head room making loading and unloading samples easy. All furnaces include a 5-ft power cord with a three-prong grounded plug. Temperature range is 200 to 1100°C and control accuracy is ±25°C. Temperature uniformity is ±10°C.