What Is a Pyrometric Cone Used For?

After a potter creates his pottery piece out of clay, the clay is placed to dry. Following the drying process it will be placed in a kiln where it is heated and hardened. Kilns are nothing more than basic containers for heat. There are a number of different kinds of kilns which are listed below:…

After a potter creates his pottery piece out of clay, the clay is placed to dry. Following the drying process it will be placed in a kiln where it is heated and hardened.

Kilns are nothing more than basic containers for heat. There are a number of different kinds of kilns which are listed below:

Periodic Kilns
Updraft Kilns
Downdraft Kilns
Sprung Arch Kilns
Catenary Arch Kilns
Hill-Climbing Kilns
Bottle Kilns
Top-Hat Kilns

There are five general categories for which kiln temperatures are calculated:

Overglaze and China Painting: 1087-1465 degrees Fahrenheit
Glass Firing: 1382-1753 degrees Fahrenheit
Low Fire Ceramics: 1798-2109 degrees Fahrenheit
Mid Fire Ceramics: 2034-2295 degrees Fahrenheit
High Fire Ceramics: 2212-2371 degrees Fahrenheit

These temperature grades are determined by small ceramic cones or bars called pyrometric cones that are meant to melt at various temperatures. Today's modern kilns enable the temperature to be controlled, and these cones are what control the temperature in the firing process. During my research I was surprised to learn that heat monitors for kilns have been used since 1,000 BC

If a potter is ready to fire a piece of pottery inside a kiln they'll use a precise cone that will melt at approximately the corresponding temperature that is called for to finalize the procedure. The cones measure heat work, which is the effect of time and temperature. The cone is nestled in the kiln so the potter can keep an eye on the project's progress, letting the potter recognize that temperatures are commensurate with his or her needs.

The numbering system can be a bit baffling at the start due to the leading zero, that could be thought of like a decimal point or a minus sign (-).

Imagine Cone 0 is 0 degrees Fahrenheit. Cone 01 can be construed at being -1 degrees, while Cone 1 can be +1 degrees. The cones that melt at lower temperatures make use of a leading zero, like 022 or 010. As the cone temperature increases the leading zero disappears while the numbers keep increasing.

Listed below are some statements that may help with understanding the numbering system:

Cone Number 022 is the cone with the lowest temperature.

Cone Number 14 is the cone with the highest temperature.

Cone Number 010 is colder than Cone Number 10.

Cone Number 10 is hotter than Cone Number 010.

Try not to feel overwhelmed if you are a novice to pottery. You can enhance your pottery skills by reading books, taking pottery classes, or just by buying a potting wheel and diving in heads first. Find more resources about pottery classes here.