How does the emissivity of the alumina effect the optical appearance with regard to color? Is it possible for most of the energy to be emitted in the IR spectrum while limited at optical wavelengths?
I recall looking at a piece of brightly glowing insulator in some NASA photo. The material was being held within a volunteer's hand and did not burn that person. Had the radiation been emitted at the level expected by the brightness, the person would have suffered severe burns. Could this process work in the other direction such as we seem to question in this discussion? Dave -----Original Message----- From: a.ashfield <[email protected]> To: vortex-l <[email protected]> Sent: Sun, Oct 12, 2014 4:39 pm Subject: Re: [Vo]:Incandescence is the wrong color Jed, As someone experienced with working at these kinds of temperatures in the glass industry, it was obvious that the temperature shown in the image is way below the reported operating temperature. I don't know whether this is because it was warming up, or because many consumer cameras don't show red hot things correctly. I am now somewhat dated, but I would have used a type S platinum thermocouple, at the reported temperature, for the reactor control and would have reported that reading as a useful check against the IR reading. I also wonder what they used for the heating element as that would have to be good for 1500C
