Tag Archives: kiln heatwork

Witness Cones for Pottery Kilns: 9 Smart Ways to Avoid Bad Firings

orton-cones-self-support-cone

Executive Summary A digital kiln controller is useful, but it is not the final authority on what happened inside your kiln. Witness cones are. A witness cone is a small pyrometric cone placed inside the kiln beside your ware. It bends in response to heatwork—the combined effect of temperature and time—not simply a temperature reading. […]

Pyrometric Cones: How to Use Witness Cones in a Pottery Kiln

kiln element resistance test

If you own a pottery kiln, pyrometric cones are one of the simplest tools you can use to find out what actually happened during a firing. Your kiln controller can tell you the temperature it measured. A thermocouple can tell the controller when to change the firing program. But neither one directly tells you the total heatwork […]