search  current discussion  categories  kilns & firing - cones & controllers 

draw rings; was: using a pyrometer

updated thu 18 jan 07

 

cliff daniels on tue 16 jan 07


Bruce, please tell more about Draw Rings. What
are they? How are they used? Would you use them
in addition to cones and Temp. readings?


--- Bruce Girrell
wrote:

> > So, if a digital meter gave a millivolt
> reading that the table
> > used by the scientific community says
> corresponds to a
> > temperature of say 1000 deg C (41.276 mv for
> the K type), do we
> > believe it or disbelieve it ? How would you
> validate this value ?
>
> Ah, now there's the $64,000 question. How many
> times do we see a post with
> something like "my pyrometer is reading X
> degrees to low/high"? Such a
> question simply underscores the lack of
> understanding in the clay community
> of what a pyrometer does. How do we know what
> temperature it "should" be
> reading?
>
> > By the way, I prefer to trust Orton cones to
> indicate an end
> > point of a firing.
>
> I'm certainly with you there. We are attempting
> to judge the degree to which
> we have melted/sintered our clays and glazes.
> Certainly something that
> undergoes controlled melting is much more
> indicative of that process than
> something that simply measures temperature,
> regardless of how accurate that
> measurement is and how close the measurement
> sensor is to the object that we
> are interested in.
>
> In addition to cones, I am increasingly liking
> the use of draw rings. Yes,
> they take up space, but they are composed of my
> clay and coated with my
> glazes. I can observe the degree of glaze melt,
> the evolution of bubbles,
> the formation of crystals, etc. with draw
> rings. I have also learned quite a
> bit about the evolution of color in the glazes
> and clay bodies.
>
> Yours in science,
>
> Bruce Girrell
>
>
______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or
> change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may
> be reached at melpots@pclink.com.
>


The Mud Man
Clifford Daniels
1 Calvin Coombs Rd.
Colrain, MA 01340
413-624-0251
mudmanpottery@yahoo.com



____________________________________________________________________________________
Food fight? Enjoy some healthy debate
in the Yahoo! Answers Food & Drink Q&A.
http://answers.yahoo.com/dir/?link=list&sid=396545367