=?iso-8859-1?Q?Fran=E7oise?= Melville on thu 28 oct 99
------------------
I see that Joanne has been advised by some to buy a digital pyrometer
(platinum/rhodium probe?) for her problematic little converted kiln.
Really, this seems to be an unnecessary added expense. I have a simple
type K, chromel/alumel analogical pyrometer for my updraft Olympic which
gives me perfectly satisfactory results using natural gas. Surely the idea
of having the pyrometer is mainly to observe the temperature rise up to red
heat=3B the desired temperature is then reached relying mainly on cones
which at this stage will be more accurate than any pyrometer. In my case
the pyrometer seems to coincide with the cones fairly well, constantly
showing 1200C when cone 6 starts bending, but I would never rely on it
entirely.
Another advantage to the analogical pyrometer is that it needs no source of
electric energy to make it work. This is really convenient if, as in my
case, one has no electrical outlet in the kilnshed, or there are fairly
frequent power outages.
Anyway, Joanne, if you do decide to get a pyrometer, digital or not, do
protect the thermocouple with a porcelain sheath. Thermocouples oxidize
and fall apart very quickly in gas kilns in even a slight reduction
atmosphere, but with the protective casing they seem to last indefinitely.
As for a pressure gauge/manometer, unless you make it yourself, I wouldn't
advise it. I nearly got one when I first installed my Olympic, but
couldn't find one locally. I thought I might order one, but after a few
firings I realized that I could quite well do without it. One just gets
to know one's kilns 'temperament'
so well that it becomes easy to adjust pressure, primary air, damper, etc.
without any kind of intsrument. I don't even have pilots and still manage
to candle.
In her very first post on this subject, Joanne wondered whether she might
have to lie down in order to deal with her burners. There is a simple
solution to this. I have a smallish mirror propped up on a brick under my
kiln. With this it is easy to see all five burners without having to
crawl around in the mud (It's always raining here and although the roof is
okay, water rushes in under the back wall and out again through the front).
Fran=E7oise, who lives in the rain capital of Canada :(
Indalo Pottery
http://indalopottery.tripod.com
Joanne Van Bezooyen on fri 29 oct 99
------------------
Francoise=21 Great idea for the mirror=21 And....you know what?....I =
found a
digital pyrometer on sale thru Axner's for =2450=21 Only problem, said =
Axner, is
it reads centrigrade only. I'll keep a chart nearby and learn to understand
centigrade better. My husband also raised the kiln up on one row of =
concrete
blocks so I don't have to lie flat on the ground (snakes and scorpions and
tarantulas...oh my=21)
As for the gas pressure gauge....I ordered one, but if I find I get to high
fire without it, I'll return it. That was =2445.
Our 4-H club's endangered species of turkey....Boboli....was hit by a car
yesterday and we have been desperately trying to save him.....swollen head,
wounds all over, half the feathers ripped out.....fever. Brett the Vet just
left. Let's pray our dear old Boboli makes it. He's a sweetheart, loved by
the whole neighborhood.
Joanne
Fran=E7oise Melville wrote:
=3E ----------------------------Original message----------------------------
=3E ------------------
=3E I see that Joanne has been advised by some to buy a digital pyrometer
=3E (platinum/rhodium probe?) for her problematic little converted kiln.
=3E Really, this seems to be an unnecessary added expense. I have a simple
=3E type K, chromel/alumel analogical pyrometer for my updraft Olympic which
=3E gives me perfectly satisfactory results using natural gas. Surely the =
idea
=3E of having the pyrometer is mainly to observe the temperature rise up to =
red
=3E heat=3B the desired temperature is then reached relying mainly on cones
=3E which at this stage will be more accurate than any pyrometer. In my case
=3E the pyrometer seems to coincide with the cones fairly well, constantly
=3E showing 1200C when cone 6 starts bending, but I would never rely on it
=3E entirely.
=3E Another advantage to the analogical pyrometer is that it needs no source=
of
=3E electric energy to make it work. This is really convenient if, as in my
=3E case, one has no electrical outlet in the kilnshed, or there are fairly
=3E frequent power outages.
=3E Anyway, Joanne, if you do decide to get a pyrometer, digital or not, do
=3E protect the thermocouple with a porcelain sheath. Thermocouples =
oxidize
=3E and fall apart very quickly in gas kilns in even a slight reduction
=3E atmosphere, but with the protective casing they seem to last =
indefinitely.
=3E As for a pressure gauge/manometer, unless you make it yourself, I =
wouldn't
=3E advise it. I nearly got one when I first installed my Olympic, but
=3E couldn't find one locally. I thought I might order one, but after a =
few
=3E firings I realized that I could quite well do without it. One just =
gets
=3E to know one's kilns 'temperament'
=3E so well that it becomes easy to adjust pressure, primary air, damper, =
etc.
=3E without any kind of intsrument. I don't even have pilots and still =
manage
=3E to candle.
=3E In her very first post on this subject, Joanne wondered whether she =
might
=3E have to lie down in order to deal with her burners. There is a simple
=3E solution to this. I have a smallish mirror propped up on a brick under =
my
=3E kiln. With this it is easy to see all five burners without having to
=3E crawl around in the mud (It's always raining here and although the roof =
is
=3E okay, water rushes in under the back wall and out again through the =
front).
=3E
=3E Fran=E7oise, who lives in the rain capital of Canada :(
=3E
=3E Indalo Pottery
=3E http://indalopottery.tripod.com
Dave Finkelnburg on sat 30 oct 99
Francoise,
I really like your very simple, common sense idea of using the mirror to
look up under the small updraft kiln. Why didn't I think of that? I've
been out there, laying in the snow, on the wet ground, grrrrrrrr....duh!
On the subject of the digital pyrometer, are you confusing the pyrometer
and the thermocouple? From all the information I have gleaned from the good
folks on this list, a heavy gauge type K thermocouple is indeed adequate,
and sufficient, and one doesn't really need to spend the money on a type R
or S thermocouple. The thermocouple, though, is only the sensor, the part
you put through the kiln wall to sense the temperature inside the kiln.
The pyrometer converts the very small electrical signal from the
thermocouple into some reading on a dial or display which you can read and
relate to temperature. Whether one prefers the analog pyrometer or digital
is mostly a matter of opinion. I won't argue with your opinion. However,
type K thermocouples can be used with either analog or digital pyrometers.
Regards,
Dave Finkelnburg in very dry Idaho (until we got a dose of rain this
week!)
dfinkeln@cyberhighway.net
-----Original Message-----
From: Frangoise Melville
To: CLAYART@LSV.UKY.EDU
Date: Thursday, October 28, 1999 11:57 AM
Subject: pyrometer for "cold" conversion kiln
----------------------------Original message----------------------------
------------------
I see that Joanne has been advised by some to buy a digital pyrometer
(platinum/rhodium probe?) for her problematic little converted kiln.
Really, this seems to be an unnecessary added expense. I have a simple
type K, chromel/alumel analogical pyrometer for my updraft Olympic which
gives me perfectly satisfactory results using natural gas. Surely the idea
of having the pyrometer is mainly to observe the temperature rise up to red
heat; the desired temperature is then reached relying mainly on cones
which at this stage will be more accurate than any pyrometer. In my case
the pyrometer seems to coincide with the cones fairly well, constantly
showing 1200C when cone 6 starts bending, but I would never rely on it
entirely.
Another advantage to the analogical pyrometer is that it needs no source of
electric energy to make it work. This is really convenient if, as in my
case, one has no electrical outlet in the kilnshed, or there are fairly
frequent power outages.
Anyway, Joanne, if you do decide to get a pyrometer, digital or not, do
protect the thermocouple with a porcelain sheath. Thermocouples oxidize
and fall apart very quickly in gas kilns in even a slight reduction
atmosphere, but with the protective casing they seem to last indefinitely.
As for a pressure gauge/manometer, unless you make it yourself, I wouldn't
advise it. I nearly got one when I first installed my Olympic, but
couldn't find one locally. I thought I might order one, but after a few
firings I realized that I could quite well do without it. One just gets
to know one's kilns 'temperament'
so well that it becomes easy to adjust pressure, primary air, damper, etc.
without any kind of intsrument. I don't even have pilots and still manage
to candle.
In her very first post on this subject, Joanne wondered whether she might
have to lie down in order to deal with her burners. There is a simple
solution to this. I have a smallish mirror propped up on a brick under my
kiln. With this it is easy to see all five burners without having to
crawl around in the mud (It's always raining here and although the roof is
okay, water rushes in under the back wall and out again through the front).
Frangoise, who lives in the rain capital of Canada :(
Indalo Pottery
http://indalopottery.tripod.com
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