dalecochoy on sat 29 mar 03
I recently purchased a Fluke 52 and two 12" thermocouples. I also bought two
of the 12" ceramic protective shields. I'm wondering if anyone HAS
EXPERIENCE with using these as I'm curious if they effect the temp readings
any at any point in the range. They completely enclose the entire length of
TC and fit pretty snuggly. My plan was to actually use high temp Selkirk
ceramic caulk ( 3,000F) that I had left from my stack install to
permanantly mold them into a couple ceramic peep plugs that I've cut open on
the ends. I thought I'd do yhis rather than drilling any more holes in the
Olynpic gas kiln rings ( although there are a couple hole-drilling spots
convieniently located in a couple rings where they've left 1/2"ish holes in
the steel sheath.) I figure the molded peep plugs will give me more choices
in where I want to use the TC's especially when loading up the kiln each
time.
Dale Cochoy, Wild Things Bonsai Studio, Hartville, Ohio
DaleCochoy@Prodigy.Net http://www.WildThingsBonsai.Com
Dave Finkelnburg on sat 29 mar 03
Dale,
I've had extensive experience with thermocouples in protection tubes in
industrial applications. A thermocouple properly installed inside a
protection tube should not affect the accuracy of the temperature
measurement.
The tube can prolong the life of the thermocouple by protecting it from
the kiln gases. That's usually why such a tube is used.
However, the tube will slow the response of a thermocouple to changes in
the temperature inside the kiln. That is the price of the protection.
If you think about it, a bare thermocouple junction will see changes in
the kiln temperature pretty fast. If you hide the thermocouple junction by
a layer of air inside a ceramic tube, it will take longer for the
thermocouple to heat up or cool down when the kiln temperature changes.
This creates a time lag between the temperature change in the kiln and the
observed temperature change on your Fluke.
How much is the time lag? You'd have to run a bare thermocouple and one
in a tube, side by side, and see. Probably a few minutes, but that's only a
guess.
Good firing!
Dave Finkelnburg on a sunny spring day in Idaho
----- Original Message -----
From: "dalecochoy"
Sent: Saturday, March 29, 2003 9:31 AM
Subject: Fluke 52 thermocouple protection question
> I recently purchased a Fluke 52 and two 12" thermocouples. I also bought
two
> of the 12" ceramic protective shields. I'm wondering if anyone HAS
> EXPERIENCE with using these as I'm curious if they effect the temp
readings
> any at any point in the range.
dalecochoy on sat 29 mar 03
Thanjks Dave. That's the kind of experienced answer I was looking for.
BTW, I doubt if the time lag , if there is one, would be much of a problem
(?). don't you agree.?
Dale Cochoy, Wild Things Bonsai Studio, Hartville, Ohio
DaleCochoy@Prodigy.Net http://www.WildThingsBonsai.Com
Specializing in power wood carving tools.
Yakimono no Kokoro bonsai pottery of hand-built stoneware
----- Original Message -----
From: "Dave Finkelnburg"
To:
Sent: Saturday, March 29, 2003 12:58 PM
Subject: Re: Fluke 52 thermocouple protection question
> Dale,
> I've had extensive experience with thermocouples in protection tubes
in
> industrial applications. A thermocouple properly installed inside a
> protection tube should not affect the accuracy of the temperature
> measurement.
> The tube can prolong the life of the thermocouple by protecting it
from
> the kiln gases. That's usually why such a tube is used.
> However, the tube will slow the response of a thermocouple to changes
in
> the temperature inside the kiln. That is the price of the protection.
> If you think about it, a bare thermocouple junction will see changes
in
> the kiln temperature pretty fast. If you hide the thermocouple junction
by
> a layer of air inside a ceramic tube, it will take longer for the
> thermocouple to heat up or cool down when the kiln temperature changes.
> This creates a time lag between the temperature change in the kiln and the
> observed temperature change on your Fluke.
> How much is the time lag? You'd have to run a bare thermocouple and
one
> in a tube, side by side, and see. Probably a few minutes, but that's only
a
> guess.
> Good firing!
> Dave Finkelnburg on a sunny spring day in Idaho
>
> ----- Original Message -----
> From: "dalecochoy"
> Sent: Saturday, March 29, 2003 9:31 AM
> Subject: Fluke 52 thermocouple protection question
> > I recently purchased a Fluke 52 and two 12" thermocouples. I also bought
> two
> > of the 12" ceramic protective shields. I'm wondering if anyone HAS
> > EXPERIENCE with using these as I'm curious if they effect the temp
> readings
> > any at any point in the range.
Edouard Bastarache on sat 29 mar 03
Hello David,
right one.
I use different types of thermocouples in every firing, K and S,
shielded or not, and that is what is always happening.
Later,
"Ils sont fous ces Quebecois"
Edouard Bastarache
Irreductible Quebecois
Indomitable Quebeker
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
http://sorel-tracy.qc.ca/~edouardb/
http://perso.wanadoo.fr/smart2000/index.htm
----- Original Message -----
From: Dave Finkelnburg
To:
Sent: Saturday, March 29, 2003 12:58 PM
Subject: Re: Fluke 52 thermocouple protection question
> Dale,
> I've had extensive experience with thermocouples in protection tubes
in
> industrial applications. A thermocouple properly installed inside a
> protection tube should not affect the accuracy of the temperature
> measurement.
> The tube can prolong the life of the thermocouple by protecting it
from
> the kiln gases. That's usually why such a tube is used.
> However, the tube will slow the response of a thermocouple to changes
in
> the temperature inside the kiln. That is the price of the protection.
> If you think about it, a bare thermocouple junction will see changes
in
> the kiln temperature pretty fast. If you hide the thermocouple junction
by
> a layer of air inside a ceramic tube, it will take longer for the
> thermocouple to heat up or cool down when the kiln temperature changes.
> This creates a time lag between the temperature change in the kiln and the
> observed temperature change on your Fluke.
> How much is the time lag? You'd have to run a bare thermocouple and
one
> in a tube, side by side, and see. Probably a few minutes, but that's only
a
> guess.
> Good firing!
> Dave Finkelnburg on a sunny spring day in Idaho
>
> ----- Original Message -----
> From: "dalecochoy"
> Sent: Saturday, March 29, 2003 9:31 AM
> Subject: Fluke 52 thermocouple protection question
> > I recently purchased a Fluke 52 and two 12" thermocouples. I also bought
> two
> > of the 12" ceramic protective shields. I'm wondering if anyone HAS
> > EXPERIENCE with using these as I'm curious if they effect the temp
> readings
> > any at any point in the range.
>
>
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