Here is a quote from the instructions given by the manufacturer of Paragon kilns:
"The cone used in the kiln-sitter will not react to heat in exactly the same way as a cone placed upright in the normal position. The weight of the actuation rod and the horizontal position will cause it to bend at a lower temperature than an upright cone. It is usually necessary to use one cone hotter in the kiln-sitter than the cone to which you wish to fire."
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