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will the real cone 6 please slump?

updated tue 16 jun 98


M Richens on mon 15 jun 98

In article <>, Al Pfeiffer
>----------------------------Original message----------------------------
>As far as using a controller and trusting it to read the temp. accurately -
>don't - repeatedly maybe. I have a Paragon controller and it typically is
>about 70 F low at C6. I use a pyrometer to periodically check what the actual
>temp is vs what the controller thinks it is. For a C7 firing I set the
>controller to 2190 (not 2264) and the orton cones agree with my pyrometer.

Hi Al,
sorry if we're in the grandmother/ suck eggs bit here but...
Don't confuse temperature with cone equivalent value. Cones and rings
are a measure of Heat Work.. not quite the same as temp more a
combination of temperature and time.
If you fire 30 degree C lower but for a longer time you will get the
same cone as a shorter fire at a higher temp.
The glaze may develop differently as well.. slight change in gloss.. not
quite removing bubbles or flattening.. colour fading a touch due to
higher temp.... you know.. those annoying little inconsistencies.

But using a pyro to recalibrate the thermocouple is a good idea anyway
on a regular basis.


Max Richens +44 (0) 1925756241
Enamel Consultant - Ceramist - Analyst programmer
Software for Batch Formulation and Millroom control.