Thermocouple Offset Setting and Cone Offset Setting

What they are, how to find them, and when to use which setting.

  1. Thermocouple Offset and Cone Offset are two different settings that allow you to control how much heat-work develops in the kiln by the end of the program. Basically they accomplish this by allowing you to raise or lower the final temperature that the DynaTrol calculates to shut itself off.
  2. The Thermocouple Offset setting allows you to add or subtract degrees from the kiln’s final temperature.
  3. The Cone Offset setting allows you to add or subtract degrees from what the DynaTrol determines the individual cone’s final temperatures to be.
  4. They are both located under the OTHER key. When the display reads IDLE, press OTHER again and again.

Cone Offset:

  1. This is used to adjust certain cones that are over or under-firing.
  2. A positive offset will increase heat work and a negative offset will decrease heat work.
  3. Cone Offset is only seldom used; for example, if the customer complains that although the glaze firing is fine, the bisque firing is too hot or too cool.
  4. Using Cone Offset on the bisque firing adjusts just a single cone number and does nothing to change the glaze firing. It is pretty rare to have to use both. Usually, they just care about the glaze firing.
  5. Another time to use Cone Offset is to get the kiln to fire to cone 5-1/2 instead of cone 5. Just add 20 to whatever is set in the cone offset already for cone 5. Then fire to cone 5 and it should be about ½ a cone hotter.
  6. First up is Cone Offset which looks like CNOS. Press ENTER here to first set which cone you want to offset, then set how much of an offset you want to have. Very early versions of the DynaTrol only came with +/-50 degrees, while later ones come with +/-100 degrees. If the setting is already set to 0 and you want the kiln to fire cooler you must use a “9” in front of the setting; 9020 would 20 degrees cooler that the 0000 setting.
  7. The cone offset may show the last cone that you fired to. The Cone offset will only change the final temperature for the cone you select. It does not change the temperature on all cones. Just select the cone value you want to put the offset on and then put in the desired offset.

Thermocouple Offset:

  1. A few OTHER presses past CNOS you will find TCOS or Thermocouple Offset. When TCOS comes up press ENTER and first you will see which TC you are about to offset. Press ENTER again and you will see how many degrees are currently offset for that thermocouple. This number is what you will be changing to make this zone of the kiln fire hotter or cooler. RAISE the setting to fire cooler, LOWER the setting to fire hotter. Use the “9” again as a prefix for a setting that is set below 0. While you can set each zone differently it is best to keep the settings within 10 degrees of each other to minimize the chances of producing an error code from the difference between an artificially higher/ lower temperature and the real set point.
  2. Thermocouple Offset and Cone Offset can both be used to calibrate the kiln to a self-standing pyrometric cone. All this means is that when you program the kiln to go to say cone 6, it will do that and bend the cone over perfectly- not too hot or cool. If the cone comes out looking too melted or not melted enough Thermocouple Offset and/or Cone Offset can be used to adjust it hotter or cooler.
  3. Lots of people call up and say the kiln fires are too hot or too cool. It seems best to first calibrate the kiln to its glaze cone using Thermocouple Offset only. This usually only takes one firing but sometimes 2 or 3 firings are necessary.
  4. If they say it fired more than a whole cone over where it should have, add 25-35 to the existing Thermocouple Offsets. If they say about a whole cone over add 20-25. If they say the cone was flat but still had the hump in the back add 15-20. 10 seems to be the minimum setting change in order to see a significant change in the cones.
  5. Thermocouple Offset is used to help even zones out or the kiln over fires or under fires evenly on every cone programmed.
  6. A positive offset will decrease heat work and a negative offset will increase heat work.
  7. A positive offset tells the control the kiln is already so many degrees warmer than it actually is. This tricks the controller and it will fire the kiln with a lower temp result. (less heat)
  8. A negative offset tells the control the kiln is already so many degrees cooler than it actually is. This tricks the controller and it will fire the kiln with a higher temp result. (more heat)


You can do both offsets.

Thermocouple offsets

  1. Negative offset to add heat work
  2. Positive offset to decrease heat work

Cone offsets

  1. Positive offset adds heat work
  2. A Negative offset decreases heat work