Test Firing - Orton AutoFire Plus User Manual

AutoFire® Kiln Controller User's Guide
The Test Firing
Completing a test firing with your new AutoFire® Kiln Controller will help you become familiar with the
operation and features of the controller, as well as determine that the controller is performing as expected.
Follow your kiln manufacturer's Instruction Manual for setting up your kiln and firing to properly break-in the
kiln's heating elements.
For an AutoFire® Plus or Pro model, place a set of Orton Self-Supporting Cones on the middle shelf in your
kiln so that they can be seen through the kiln peephole. If you have the AutoFire® UniTemp™ model controller,
also place cones on the top and bottom shelves of kiln to examine temperature uniformity within your kiln. Use
a series of cones close to the temperature that you plan to fire to during an actual firing. A three cone firing set-
up is recommended, a Guide Cone, Firing Cone, and a Guard Cone. For example, if you were firing to a
1945°F (Cone 04), you would use a Cone 03, Cone 04, and a Cone 05, to do the test firings.
To evaluate heat distribution, place a set of witness cones on each shelf during the test firing. Most kilns fire
more uniformly at Cone 6 than they do below Cone 06. With the UniTemp™, cones should bend similarly, no
matter what the firing temperature.
Provide ventilation for the kiln in accordance with your kiln manual or Orton KilnVent® instruction manual.
If your kiln has limit switches, turn all switches to the "On" or "highest" position. Begin the firing, refer to
page 7 of this manual for using preset cone programs.
After the firing, before opening the kiln to remove your cones, make sure the kiln has cooled sufficiently.
Examine the fired cones. Some variation in the bending of the cones may occur, depending on how the kiln was
loaded. This includes the size of the load, its distribution on the shelves and the location of the cones. It is a
good practice to use a witness cone in every firing. This provides a permanent record of the firing conditions in
the kiln and can help you identify changes in the way your kiln is firing.
Test fire approximately every 25 firings. Test conditions should be consistent from firing to firing. Save the
sets of witness cones as records of the firings. Review them periodically to note variations or drift in successive
firings.
If thermocouple drift starts to occur, recheck the heat distribution. If one area of the kiln is much hotter or
cooler than another, it may indicate that one or more heating elements need replaced.
If there is a major change in the amount of bending of the firing cone, the most likely cause is thermocouple
damage or deterioration. Replace the thermocouple and retest. If replacing the thermocouple does not restore
the performance to previous levels, the controller or kiln may require additional service.
The Cone Offset feature (see page 15) can be used to adjust the temperature of a cone firing to more closely
match the bending of a cone.
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