Part 4/7:
With the kilowatt thermocouple, the temperature was reported at 1,470°F, while the Williamson recorded a significantly higher temperature of 15,252°F. Both devices were within a reasonable range, prompting Ryan to explore further by opening the kiln door to observe how the surface temperature would change upon cooling.
Effects of Cooling on Emissivity
When they opened the kiln, a visible glow from the heated material was evident, but Ryan took caution due to the extreme heat within the kiln. He noted a significant drop in emissivity as the door was opened, observing it decrease to 0.9. This shift occurred while measuring the emissivity directly at the material surface.