A pyrometric cone is a three-sided pyramid composed of ceramic materials formulated to bend and deform in a repeatable manner at a specific temperature. These cones serve as visual indicators of heat work within a kiln during firing. The degree of bending reflects the combined effects of temperature and time, providing a more accurate representation of the heat treatment experienced by the ware than temperature alone.
The value of such cones lies in their ability to integrate temperature and time, offering a reliable assessment of the thermal history of a firing. This is particularly important in ceramic production, where the vitrification process, and therefore the final properties of the ceramic, depend on the cumulative effect of heat over time. Historically, they have been crucial in ensuring consistent results in the production of ceramics, from earthenware to high-fired porcelain, reducing variability and improving the predictability of the firing process.
