Wayne Seidl on tue 31 may 05
That's possible, Louis, but unlikely.
K.I.S.S. applies, generally. =20
Sandy:
---When did you last put a new battery in it? Are the battery
connections corroded?
---Has it been dropkicked across the studio? Dropped in a glaze
bucket? Gotten wet, or hammered?
---Did you check to see that the connections where the wires attach
to the unit (not the thermocouple, but the meter part) are clean and
tight?
The indicator is "...sulked for a while and showed no temps at
all..."
Just my 2=A2
Wayne Seidl
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Louis
Katz
=20
I would call or write Bartlett,
I would also unplug the controller and replug it in after several
hours
in case some volitile memory has somegoofed up number in it.
Louis
On May 31, 2005, at 7:28 PM, Sandy Henderson wrote:
> Hi, everyone --
> My pyrometer appears to be having a nervous breakdown.
> A couple of years ago I took my first step toward joining the
digital age of electric kilns and bought a Bartlett pyrometer for
my little Skutt kiln.
> It has probably been through 100-150 firings. This last firing
> (yesterday), it began by giving impossible numbers like 19956,
then sulked for a while and showed no temps at all. But about
midway through the firing, it started behaving and worked fine until
the end.
>
> I know that thermocouples go bad, but I thought that the usual
> symptom was a "drifting" of readings, not a total breakdown. Is
this a
> different problem?
>
> Thanks for any advice --
> Sandy Henderson
> in northwest Indiana
Sandy Henderson on tue 31 may 05
Hi, everyone --
My pyrometer appears to be having a nervous breakdown.
A couple of years ago I took my first step toward joining the digital age
of electric kilns and bought a Bartlett pyrometer for my little Skutt kiln.
It has probably been through 100-150 firings. This last firing
(yesterday), it began by giving impossible numbers like 19956, then
sulked for a while and showed no temps at all. But about midway
through the firing, it started behaving and worked fine until the end.
I know that thermocouples go bad, but I thought that the usual
symptom was a "drifting" of readings, not a total breakdown. Is this a
different problem?
Thanks for any advice --
Sandy Henderson
in northwest Indiana
Louis Katz on tue 31 may 05
I would call or write Bartlett,
I would also unplug the controller and replug it in after several hours
in case some volitile memory has somegoofed up number in it.
Louis
On May 31, 2005, at 7:28 PM, Sandy Henderson wrote:
> Hi, everyone --
>
> My pyrometer appears to be having a nervous breakdown.
>
> A couple of years ago I took my first step toward joining the digital
> age
> of electric kilns and bought a Bartlett pyrometer for my little Skutt
> kiln.
> It has probably been through 100-150 firings. This last firing
> (yesterday), it began by giving impossible numbers like 19956, then
> sulked for a while and showed no temps at all. But about midway
> through the firing, it started behaving and worked fine until the end.
>
> I know that thermocouples go bad, but I thought that the usual
> symptom was a "drifting" of readings, not a total breakdown. Is this a
> different problem?
>
> Thanks for any advice --
> Sandy Henderson
> in northwest Indiana
>
> _______________________________________________________________________
> _______
> 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.
>
>
Louis Katz
http://www.tamucc.edu/~lkatz
Jim Willett on wed 1 jun 05
Sandy my guess is the thermocouple is worn out. A thermocouple is made by
joining two dissimilar metals together and the weak point is the joining
point. Where the wires are soldered or welded the connection can begin to
break down. As the temperatures start to rise the metals expand and the
connection is stronger, for awhile. I would suggest a new thermocouple
will cure your problem.
Jim Willett
http://www.outofthefirestudio.com
Earl Brunner on wed 1 jun 05
From: Steve Mills
Subject: Re: pyrometer problem
Sandy,
you have just described a pyrometer/thermocouple set with a broken
connection somewhere between the two.
From experience I would suggest you first look at the connection
between
the thermocouple and its extension cable, and then the connection at
the
other end of the cable.
Steve
Bath
UK
Earl Brunner
e-mail: brunv53@yahoo.com
Bob Masta on wed 1 jun 05
Sandy:
The numbers drifiting skyward can be a symptom of a bad
connection. Try wiggling the thermocouple connector slightly
while watching the readout, and see if the problem comes
and goes. You should be able to do this test with the
system cold.
However, I have seen this symptom on thermocouples that
were on their dying legs. These were home-welded from
rather thin K-type wires, and they tended to oxidize rather
quickly. By the time they started this quirky behavior, upon
removal from the protective ceramic tube they had become
extremely brittle at the hot end, like little black chow mein noodles.
Hope that's not the case here!
Bob Masta
potsATdaqartaDOTcom
| |
|
