elark1@VERIZON.NET on wed 26 may 04
i fired my cone-art kiln last nite. it has a computer controller added on
after purchase so i have drilled a hole thru the steel jacket and the wall to
introduce the thermocouple into the kiln. so far i have cut and shaped a small
piece of soft brick to protedt the thrmocouple from touching the sttel wall.
it is a real pain to keep this plug workin, in place and also from breaking
apart after repeated firings. my question is --is tis necessary? can i just
introduce the thermocouple and also it to rest on the steel or will that give
me a false reading. what do other people do about protecting the thermocuple.
i would love to hear from other regarding this "problem". i am being a bit
paranoid regarding the thermo and the metal skin....
tia,
eleanor arkowitz,
in grey, wet and damn cold n.h. (43 degrees this a.m.)-where or where is
spring???
Arnold Howard on wed 26 may 04
The thermocouple with the metal sheath will give less accurate readings if
the sheath touches the kiln's steel case. The thermocouple must remain
ungrounded.
My suggestion for installing the thermocouple: Make the hole in the steel
case slightly larger than the hole in the firebrick wall. If the
thermocouple is 1/4" wide, the firebrick hole should be 1/4" and the hole in
the steel case should be around 3/8". Since the hole in the steel is larger,
the thermocouple won't be in contact with the steel case.
First, drill the 1/4" hole in the steel case and firebrick wall. (Make sure
that you stay away from firebrick grooves.) Then drill the larger hole in
the steel case using the 1/4" hole as a starting point.
Sincerely,
Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
arnoldhoward@att.net
From:
> i fired my cone-art kiln last nite. it has a computer controller added on
> after purchase so i have drilled a hole thru the steel jacket and the wall
to
> introduce the thermocouple into the kiln. so far i have cut and shaped a
small
> piece of soft brick to protedt the thrmocouple from touching the sttel
wall.
> it is a real pain to keep this plug workin, in place and also from
breaking
> apart after repeated firings. my question is --is tis necessary? can i
just
> introduce the thermocouple and also it to rest on the steel or will that
give
> me a false reading.
BobWicks@AOL.COM on wed 26 may 04
In a message dated 5/26/2004 5:13:44 PM Eastern Daylight Time,
arnoldhoward@ATT.NET writes:
> The thermocouple with the metal sheath will give less accurate readings if
> the sheath touches the kiln's steel case. The thermocouple must remain
> ungrounded
I think Arnold meant Porcelain sheath on the thermal coupling. I have never
seen a metal sheath on this as it surely would short it out. This must be a
non conductor.
Bob
Nancy Chiasson on thu 28 feb 08
My kiln has suddenly flashed an EEEE message, which the manual suggests is
the thermocouple. I guess this is a no brainer. How long does a
thermocouple last?
Thanks.
Nancy Chiasson
www.nancychiasson.com
William & Susan Schran User on thu 28 feb 08
On 2/28/08 8:57 AM, "Nancy Chiasson"
wrote:
> My kiln has suddenly flashed an EEEE message, which the manual suggests is
> the thermocouple. I guess this is a no brainer. How long does a
> thermocouple last?
The simple answer is it lasts until it fails.
I'm not trying to be a wise ass about this, but without knowing what type of
thermocouple (I suspect it's a "K"), whether it's in a sheath, what
temperature the kiln is usually fired to, the kiln atmosphere and how many
firings the thermocouple has been exposed to it's very hard to give you an
educated guess.
A bare (you just see a twist of metal) type "K" thermocouple fired to bisque
& ^6 temperatures will probably last a couple years of firing, depending how
many firings take place over that span of time.
A bi-metal thermocouple (looks like a straight metal rod with rounded end)
will probably last longer. I have one of those in a kiln that I use just for
bisque firing and have been using it for 7 years.
A thermocouple in a ceramic sheath may, or may not last longer. The type "K"
that's in a ceramic sheath fired in our gas kiln at school to ^10 failed
after 18 months.
The platinum thermocouple in a ceramic sheath in my kiln I use for
crystalline firings only to ^6 may out live me.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Donald Burroughs on sat 1 mar 08
Hi Nancy
How long a thermocouple lasts will depend on it's composition and whether
it has a decent shield. You didn't indicate if this is the original and
how long you have had the controller (kiln). How often do you fire? Also,
a consideration is how many times have you accidentially bumped in to the
thermocouple. We all do this no matter how careful we are. Another thing
to check would be your relays. Make sure they are all working. I'm
assuming that you have the PerfectFire controller (the original by
Canadian Instrumentation).
Regards Don :)
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