Pyrometric cones have been used to monitor ceramic firings for more than 100 years. They are useful in determining when a firing is complete, if the kiln provided enough heat, if there was a temperature difference in the kiln or if a problem occurred during the firing. Cones are made from carefully controlled compositions. They bend in a repeatable manner (over a relatively small temperature range - usually less than 40° F). The final bending position is an indication of how much heat was absorbed. 

Orton pyrometric cones are used worldwide to monitor ceramic firings in industrial kilns, pottery kilns, and small hobby kilns where the consistent temperature is important to the quality of the final product being fired. Orton Pyrometric cones measure heat-work, the effect of time, and temperature.  Over time, kilns sometimes drift from their setpoint even though "Nothing has changed".  Pyrometric cones will be the first to let you know your ceramic firing is under control or that subtle changes are taking place within your kiln, allowing you to take corrective action before they impact your ware.

Utilize the Orton Cone Temperature Equivalents Chart to select the correct cone numbers you will need. Selecting Orton's self-supporting cones will solve the issue of correct mounting height and angle for you.

For further assistance selecting the proper cone, see "Selecting Cone Types" at Pyrometric Cones - Resources.