Pyrometric cone

The cones, often used in sets of three, are positioned in a kiln with the wares to be fired and, because the individual cones in a set soften and fall over at different temperatures, they provide a visual indication of when the wares have reached a required state of maturity, a combination of time and temperature.

The three-cone system consists of three consecutively numbered cones: Additionally, most kilns have temperature differences from top to bottom.

Additionally, small cones or bars can be arranged to mechanically trigger kiln controls when the temperature rises enough for them to deform.

Precise, consistent placement of large and small cones must be followed to ensure the proper temperature equivalent is being reached.

[3] Pyrometric cones are sensitive measuring devices and it is important to users that they should remain consistent in the way that they react to heating.

In 1782, Josiah Wedgwood created accurately scaled pyrometric device, with details published in the Philosophical Transactions of the Royal Society of London in 1782 (Vol.

[14][15] The Standard Pyrometric Cone Company was founded in Columbus, Ohio, by Edward J. Orton, Jr. in 1896 to manufacture pyrometric cones, and following his death a charitable trust established to operate the company, which is known Edward Orton Jr.

The following temperature equivalents for pyrometric cones were retrieved from references in the External Links section.