These infrared heaters are made out of ceramics. These emitters have a Nichrome (NiCr) wire directly casted into ceramic and they produce temperatures from 300 deg F to 750 deg F. The wavelength produced with at these temperatures is between 3 – 6 microns. They feature a glazed surfaced to avoid for protection from oxidation and corrosion. Typically they need 10 – 15 minutes to reach full operating temperature. A thermocouple can be casted directly into the ceramic. Ceramic heaters come in different colors which may indicate the temperature range. Some of these heaters also change color when hot in order to easily recognize failed elements in a heater bank.
They come in different shapes. A flat surface spreads the infrared energy over a wider area, while a concave surface focuses the energy more to a desired spot.
Ceramic heaters are used for comfort heating, saunas and for industrial heating application requiring lower temperatures.
On the last picture on the right side: Forty IR heaters are mounted on a stainless steel parabolic fixture. Integral Thermocouples in the heaters were part of the five control zones which included PID controllers and SCR power switching. Additional hi-limit circuits ensured the unit could not overheat.