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subject: new kiln questions

updated thu 24 feb 05


denny means on wed 23 feb 05

Jean, a new kiln can be a joy, but there does seem to be a getting-to-know-you period. When I got a similar sized L&L kiln, I noticed that my specific kiln was not bending the cones full over. I delved into the owner's manual and discovered the “thermocouple offset,” or tCOS on the control window. This setting is used “to raise or lower the temperature indicated by the thermocouples.” By watching the cones over several firings, I adjusted the tCOS from the factory setting of + 50 degrees (F.) to zero. Raising the indicated temperature of tCOS lowers the temp. in the kiln and reduces the amount of heat work. I had to lower the indicated temp. of tCOS, thus increasing the amount of heat work that the computer called for.

Since the L&L kiln has 3 thermocouples, the bottom, middle and top sections of the kiln can each have their offsets adjusted to even out the kiln and provide more uniform heat work to the ware.

 Another setting that can be useful is "cone offset.” This setting, some form of which is incorporated into most computer controllers allows you to fine tune your kiln for specific cones that you fire to. The Cone Offset (CnoS) is used to tell the computer “what the final cone temperature should be” in the computer program.

Making adjustments to your controller will pay long-term dividends and let the kiln fire more evenly.

The time of firing will vary with the load, part of this variance is the Orton software used by the computer to adjust the final temperature based on the speed of the firing, when you use a preprogrammed firing routine.


 The dealer set my kiln up and they shimmed the feet with wood pieces. The small wedges adjust for unevenness in the concrete floor. Most importantly, the weight of the kiln is evenly distributed to all four legs, which will help limit cracking of the kiln bricks, etc. Shimming the kiln legs may help somewhat with the lid problem.  The lid should have some adjustment on it to allow it to close, but I can’t help with that one.

  Keep trying the manufacturer’s support number – you may have to call several times to find a tech that can help you. Meantime, there’s the dreaded owner’s manual.

Good Luck,


Denny Means