All you need to know about cones!
From our friends @ Orton Controllers...
Pyrometric cones are used worldwide to monitor ceramic firings in industrial kilns, pottery kilns, and small hobby kilns where consistent temperature is important to the quality of the final product being fired.
Although Orton pyrometric cones were developed in the late 1800's to provide the ceramist with a tool to measure the firing of ceramic products, cones have stood the test of time and continue to provide verification of the combined effect of time and temperature (heatwork) on ceramic products around the globe. The development of electronic controllers paired with thermocouples has certainly proved invaluable in the control of the firing cycle of ceramic kilns, but the controllers cannot measure heatwork.
Most ceramic products are no more sensitive than the cone to temperature since they share many of the same ingredients... Cones and Firing - a practical guide to successful firings.
The value of the cone is to provide verification that the kiln is delivering the expected amount of heat work each time a specific heating profile is applied and verify that the heat work is being delivered uniformly within the kiln ware load when multiple cones are placed within the load setting.
Utilize the Orton Cone Temperature Equivalents Chart to select the correct cone numbers you will need.