Can I use this pyrometer to check the temp in my kiln?

ajwhite · #1 2007-07-19, 2:06pm

Hi

I am pretty much positive my kiln is running way hot. I have my temp set at 940 so as not to burn the color out of my Terra beads (which have burnt out two days running now). I took a component out which I expected to crack and it went back into the torch without any problem - so it has to be alot hotter than 940 in there.

Can I use a dig. pyrometer like this
http://tinyurl.com/yoeo4n

I know I could try the slumping a rod of white and I could look into cones but I would really rather have a number - even if that number is off by 75 degrees or so it would at least give me a starting point.

I don't want to buy this thing unless it will work - it is said to go up to 1300 degrees and I have an AIM kiln so I should be within range.

Thanks
Audra

AKDesigns · #2 2007-07-19, 2:12pm

I curious too if that will work. How much is it and where did you find it?

ArtcoInc · #3 2007-07-19, 3:13pm

The pyrometer probably will work. But, I'm not sure that the thermocouple will.

If the thermocouple unplugs, you can plug in one that will tolerate the heat.

I carry a similar hand-held pyrometer: http://www.artcoinc.com/pyrometer.php. It uses the industry standard mini plug for the thermocouple. I specifically say that the teflon insulation on the supplied thermocouple won't work in a kiln application. But, you can easily (and not to expensively) get a thermocouple that will work in a kiln, and then plug it into this pyrometer.

I guess I'm going to have to start carrying thermocouples.

Malcolm

AKDesigns · #4 2007-07-19, 4:11pm

Quote:

Originally Posted by ArtcoInc

I guess I'm going to have to start carrying thermocouples.

Malcolm

Better yet just rig the whole thing up for us and sell it as a kiln tester.

ajwhite · #5 2007-07-20, 5:48am

Thanks for the reply. I figure for the money it wouldn't hurt to try. If that thermocoupler won't work I'll look into a higher temp one. (I thought I'd just stick it in through the bead door since that is where I need the temp checked anyway.

I just need a ballpark number to work with. I bumped my program down to 840 yesterday and my Terra bead faded but did not go to icky yellow/brown like before so I must be getting closer. I just want to make sure I am still annealing the beads and not catering to the Terra glass.

I'll keep you posted on my experiment when the pyrometer thingie gets here.

Audra

ajwhite · #6 2007-07-20, 5:53am

Malcom
If you wouldn't mind - where can I puchase the appropriate thermocoupler. I have no clue what to look for.

Thanks
Audra

Hayley · #7 2007-07-20, 8:02am

Audra -

Sigrid (Squid) had the same issue with her kiln with Van Gogh and got a pyrometer from Ron (R4Glass) to test her kiln. I tried to get one from Ron but he has been out. PM her the brand/model and maybe you can pick one up from somewhere else.

Hayley · #8 2007-07-20, 8:02am

Malcolm -

A kiln testing kit is a great idea!!! With instruction, please.

squid · #9 2007-07-20, 9:08am

Quote:

Originally Posted by Hayley

Audra -

Sigrid (Squid) had the same issue with her kiln with Van Gogh and got a pyrometer from Ron (R4Glass) to test her kiln. I tried to get one from Ron but he has been out. PM her the brand/model and maybe you can pick one up from somewhere else.

The one I bought is called a K2 and you can buy it other places also.

It's this one:

http://cgi.ebay.com/NEW-DIGITAL-PYRO...QQcmdZViewItem

http://www.amazon.com/489015-Digital.../dp/B000NLX7RE

http://www.tool-specials.com/shop.ph...tem=B000NLX7RE

but you might be able to find it cheaper.

Keep in mind that the accuracy of the pyrometer is important. The one show earlier was listed at 5% at 1200 degrees, which means it could be off by as much as 60 degrees. I was told that the one I bought was accurate to within 15 degrees. The thermocouple that comes with the one above is also perfect for kiln temp testing as it is long enough to get well into most kilns.

Hayley · #10 2007-07-20, 9:09am

Thanks, Sigrid!!!

squid · #11 2007-07-20, 9:12am

also down on this page

http://www.clay-king.com/pyrometer.htm

temporarily out of stock - but they are good to work with.

squid · #12 2007-07-20, 9:14am

ok - I found the official model # - it is

DT2-7 and if you google DT2-7 pyrometer:

http://www.google.com/search?sourcei...%2d7+pyrometer

you get a few more hits

squid · #13 2007-07-20, 9:15am

looks like the price is about $75 everywhere.

Diane (clarus) · #14 2007-07-20, 1:31pm

Malcolm - I wish I had seen your pyrometer - I just bought one of the K2 pyrometers but had been looking for a cheaper alternative.

FYI, I bought mine from Tracy's Stained Glass Workshop:

http://www.tracysworkshop.com/pc-192...pyrometer.aspx

where it was $59.95 plus about $10 shipping. She has a 3% off coupon listed in the coupon section of her home page - not much but every little bit helps. She shipped it out right away.

-Diane, the bargain hunter

ArtcoInc · #15 2007-07-20, 3:15pm

When I get back from the Gathering, I'll look into what it'll take to make up a batch of thermocouples.

Malcolm

ajwhite · #16 2007-08-12, 7:00am

Well I tested the pyrometer I bought on ebay and it does not work for my kiln. When my kiln read 800 it was only reading at 630 and I know that is definately wrong. If anything my kiln is running way too hot!

The end of the pyrometer isn't removeable and now it is all melty because for some reason I didn't think about the plastic handle when I stuck it in the bead door.

Malcom - is there anyway to change out the thermocoupler or am I DOOMED!

Maybe it was the wrong thermocoupler to test a kiln?

It did guage the temp of the air in the house correctly so it must be good for something - just not sure what.

Man this is frustrating!!!

squid · #17 2007-08-12, 8:50am

what kind of pyrometer did you buy and what kind of thermocouple does it have on it?

ajwhite · #18 2007-08-12, 4:13pm

Quote:

Originally Posted by squid

what kind of pyrometer did you buy and what kind of thermocouple does it have on it?

If you click the link on my first post it will take you to the ebay page with the specs on it. It says the thermocouple is good to 1300 degrees. (?)

squid · #19 2007-08-12, 5:13pm

it appears that that thermocouple is permanently attached, not interchangeable. It appears that only the tip is supposed to be inserted. The K2 comes with an 8" thermocouple that can take the heat fully inserted. If the plastic is melted, it's likely toast - sorry. Perhaps the people you bought it from can help?

smutboy420 · #20 2007-08-15, 9:18am

For a few dollars more. If you get a digital kiln controller. It not only will tell you an accurite temp it will also hold it at the temp you want it to hold at.

A digital setpoint controller is $200 including shipping and warranty.

ajwhite · #21 2007-08-15, 10:18am

My kiln has a digital kiln controller. However, I am fairly positive it is innacurate by at least 200 degrees. That is why I wanted the stand alone pyrometer to double check. I don't really want to buy another digital kiln controller to replace my Bartlett right now. Thanks though.

Audra

ArtcoInc · #22 2007-08-15, 3:02pm

Quote:

Originally Posted by ajwhite

My kiln has a digital kiln controller. However, I am fairly positive it is innacurate by at least 200 degrees. That is why I wanted the stand alone pyrometer to double check. I don't really want to buy another digital kiln controller to replace my Bartlett right now. Thanks though.

Audra, a pyrometer can be used to measure the temperature within your kiln. But, it will only give you a number, and that number can vary, depending on where the thermocouple is located within the kiln: in the center, near an edge, near the top, near the bottom, close to the elements, etc. What you really want to know is: is my kiln at the proper temperature for my glass. It doesn't matter if the pyrometer reads 986° or 98.6°, if your kiln is at the right temperature for your glass, it's at the right temperature.

Try this. This will give you better results than any pyrometer or cones can:

Pull some thin stringers of your glass. Pull some black, some white, and whatever other color you use the most. Put two heat proof objects (ie: kiln posts) in the center of your kiln, about 2" apart. Now, take a 3 inch or so length of each stringer, and suspend it across the two kiln posts, like this:

---
| |

You should have three stringers (one of each color) suspended on top of the kiln posts.

Set your kiln to 900°, and heat it up. Hold it for, oh, 15 minutes. Has the glass sagged? If not, raise the temperature 25°, and hold for another 15 minutes. Repeat until the glass starts to sag. When you find the temperature where your glass begins to sag, back off 25°-50°. You've now found your upper limit for *your* glass in *your* kiln.

You will probably find that one color will start to sag before the others. This is good to know, don't you think?

But, to go one better, try this in 5 places in your kiln: one in each corner, and one in the center. This way, you can see if you have hot spots or cold spots. If you have 10 kiln posts, you can test all 5 spots in one test.

And, if you think that the 25 degree increment is too course, after you run the first test, you can always run it again. You now know the where to begin (the last step before things started to sag). Start there, and raise the temperature by 5 degrees each time.

Oh, and run these tests again any time you are having annealing problems. Use this test as a benchmark. You need to get to know *your* kiln. Play with it. See what it can do. Don't get hung up on the numbers. Find what works for you, your glass, and your kiln.

Malcolm

smutboy420 · #23 2007-08-19, 9:45am

Ok I din't know you already had a digital controller on it yet.

The temps your thermocouple are reading should be pretty close to the right temp.
within 20 degrees +/- if its a poorly done thermocouple. and well made on should be within 3-5 degrees.

But the thermocouple reading will be relivant to where it is in the kiln.
So it may be reading one temp while anouther part of your kiln is much hotter and another may be cooler.

Can you remove your thermocouple from your kiln? or is it stuck behind a bunch of other stuff not allowing that?

If you can take it out. one sure way to test if a thermcouple is reading any were near right is to put it in a pan of hard boiling water. It should be 212F give or take a degree due to elevation and presssure. Then if you know your thermcouple Does indeed work and read right. Then you can rule that out try and find a better location for the thermcouple to take its reading from inside the kiln.

ajwhite · #24 2007-08-19, 3:15pm

That is a really great tip with the boiling water. I just tried to pull my thermocouple out but there is a collar around it preventing it from being pulled through the kiln wall. I have an AIM 84BD with a Bartlett 3 key controller. The thermocouple is located at the very top of the kiln and my beads go in the very bottom. Since heat rises I'm assuming it is hotter at the top than the bottom. I don't see a way to move the thermocouple to a different place - I can't even move it farther in toward the center. (I tried that and then ended up venting out some noxious burning plastic insulation that wasn't supposed to be shoved in a kiln - DUH)

Malcom - I will try the stringer thing when I'm not so pressed for time. That would be good information to know. I'm just hell bent on the numbers because I want to make sure I'm annealing withing the correct range. Also when doing PMC I want to make sure I'm at the right temp so the silver is strong.

I am guessing I bought the wrong pyrometer - or at least a crappy one. I may look into the one Squid has. I just hate to dump money into this stuff, I'd rather buy glass!

Thanks for all the help!