■ The oven is heated by number of electric heater of 4 of 6kw each. Each heating element is wound on a ceramic core and enclosed in a steel tube to prevent damage. The number of heaters varies with the heat rate required of the oven, and for high heat inputs may be supplemented by finned rod type heaters. The heaters have there electrical load controlled by thyristers, so that continuous, stepless by controll by thermostatic means is achieved throughout the range from zero to full power. Also, the rate of heat from top to bottom, and left to right, of a zone can be adjusted. Each zone is controlled by a control panel sited along the oven.
