Bevelynn Harris on wed 31 mar 99
Being a self-taught potter, I do not understand clearly some things that I
read. one of them being a clear understanding of temperature and its effects
on cones.if a cone is rated a say, cone 10-temp. equivalent to 2380 and this
cone bends at a much lower temp. than indicated by the pyrometer, has the
clay matured to 2380 or is it lacking in someway. I know that the speed of
heating will effect the cones , but if a clay needs to reach cone 10 to
vitrify does it if the cone falls well before the pyrometer reaches 2380?
Dannon Rhudy on wed 31 mar 99
Molly, pyrometers are notorious for being inaccurate, especially in the
upper ranges. You can adjust the pyrometer to some degree.
But if there is a difference, the cones should be your guide. They melt
according to TIME as well as TEMPERATURE, and should not be off more
than a very, very small amount.
Dannon Rhudy
potter@koyote.com
At 08:44 AM 3/31/99 EST, you wrote:
>----------------------------Original message----------------------------
>Being a self-taught potter, I do not understand clearly some things that I
>read. one of them being a clear understanding of temperature and its effects
>on cones.if a cone is rated a say, cone 10-temp. equivalent to 2380 and this
>cone bends at a much lower temp. than indicated by the pyrometer, has the
>clay matured to 2380 or is it lacking in someway. I know that the speed of
>heating will effect the cones , but if a clay needs to reach cone 10 to
>vitrify does it if the cone falls well before the pyrometer reaches 2380?
>
David Woodin on thu 1 apr 99
The answer to your question is yes. The cones measure the heat work done on
the glaze and clay and can fall at a lower temperature if the ramp to
temperature is slower than the cone tables indicate.
David
Steve Hum on thu 1 apr 99
I would always follow the cone. Pyrometers are not that accurate in my
experience.
Hum
>----------------------------Original message----------------------------
>Being a self-taught potter, I do not understand clearly some things that I
>read. one of them being a clear understanding of temperature and its effects
>on cones.if a cone is rated a say, cone 10-temp. equivalent to 2380 and this
>cone bends at a much lower temp. than indicated by the pyrometer, has the
>clay matured to 2380 or is it lacking in someway. I know that the speed of
>heating will effect the cones , but if a clay needs to reach cone 10 to
>vitrify does it if the cone falls well before the pyrometer reaches 2380?
Stephen Mills on fri 2 apr 99
Bevelynn,
A Pyrometer measures the temperature in the Kiln at the moment when you
look at it. Cones measure accumulated heat work. So when the cone 10 in
my Kiln is flat, my pots are nicely cooked, even if the Pyrometer says
1200oC (2380F). I'm of the school that uses a pyrometer to tell me how
fast I'm firing, but uses cones to tell me when to shut down.
Steve
Bath
UK
In message , Bevelynn Harris writes
>----------------------------Original message----------------------------
>Being a self-taught potter, I do not understand clearly some things that I
>read. one of them being a clear understanding of temperature and its effects
>on cones.if a cone is rated a say, cone 10-temp. equivalent to 2380 and this
>cone bends at a much lower temp. than indicated by the pyrometer, has the
>clay matured to 2380 or is it lacking in someway. I know that the speed of
>heating will effect the cones , but if a clay needs to reach cone 10 to
>vitrify does it if the cone falls well before the pyrometer reaches 2380?
>
--
Steve Mills
Bath
UK
home e-mail: stevemills@mudslinger.demon.co.uk
work e-mail: stevemills@bathpotters.demon.co.uk
own website: http://www.mudslinger.demon.co.uk
BPS website: http://www.bathpotters.demon.co.uk
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