Now and again I get rather suspicious of the temperature the kiln claims to be at. I've noticed when it's at low tempertures it seems to register that it's about 10 degrees hotter than it really is. I have a thermocouple on a meter and when I've checked it with that they both seem to agree once they've hit about 200 deg c - however the probe I have doesn't have insulation that can cope with anything over about 500 so it's difficult to double check when I start getting up to boro annealing temperatures. I've even taken to putting an off cut of clear rod in the kiln as it's easier to check before/after with a polarizing filter that things have annealed that way. Are pyrometric cones the only way I can double check if it's reading the right temperature? Or is there some other clever test I don't know about? ??? ??? ???
I know Warm Glass have started selling a testing kit Glenn, using cones (like they use in ceramics) - not sure exactly what temperatures its testing for though, it may be to measure up at fusing temperatures?
ETA: Its this one Glenn, but it specifically says for Bullseye, so I suspect its measuring fusing temperature range.
http://www.warm-glass.co.uk/kiln-test-kit-p-3490.html (http://www.warm-glass.co.uk/kiln-test-kit-p-3490.html)
Cones are definitely the way to measure though, so probably worth contacting Lee to see if they have any, otherwise I can give you a few ceramics companies to try.
Errrr yes and no.
Cones are not specifically accurate to temperature, but, maybe more significant as they give indication of "heat work" done. which, at the end of the day is exactly what your glass reacts to.
A digital controller will show 500c constantly if the kiln is left at 500c for a day or two. The exact temperature.
If the same kiln is held at 500c but with a 600c cone in, after a day or so the cone will go over as if it has been to its classified 600c. The kiln obviously hasnt been to 600c but the amount of "heat work" done on the cone has given the same effect.
An extreme example I know but what I'm getting at, is, in my long in the tooth experience, when cones and digital are compared they rarely add up.
I'm just doing a test on a kiln now and I am using 4 digital readings and the kiln is only a foot wide. If I chucked a cone in there it would throw the whole lot into the open lol.
If you are to use a cone, then you need to put it through exactly the same firing cycle as you would usually use. When the cone gives you the result you want, note the temperature on the control and at least you will then have a referance point to work to.
Oops, I stand corrected! I was of course, looking at it from a ceramics/glass fusing point of view.... ;D ;D
Quote from: Zeldazog on February 16, 2012, 11:34:08 AM
Oops, I stand corrected! I was of course, looking at it from a ceramics/glass fusing point of view.... ;D ;D
Dawn, I dare never correct you my learned friend ;D ;D
I think I understand, besides for what I can tell the lowest cone I can find is about 574, which is slightly higher than 566/567 that I am looking to hit, but might be close enough to give me an idea. I'll pull out the probe and start poking the kiln again.
However, what it really tells me is something I already know from the various problems I've had over the years with this kiln........... wish I'd have bought a kilncare kiln to start with ::) :-[
I have this guy that I use if I'm doing complicated stuff! Requiring know what's going on in two heights or places in the kiln.
http://www.warm-glass.co.uk/k2-digital-pyrometer-p-2409.html
Quote from: Flyingcheesetoastie on February 16, 2012, 12:41:00 PM
I have this guy that I use if I'm doing complicated stuff! Requiring know what's going on in two heights or places in the kiln.
http://www.warm-glass.co.uk/k2-digital-pyrometer-p-2409.html
That looks like just the ticket! I'm suspecting parts of the kiln aren't all the same temperature, so that'll tell me in a jiffy. Thank you!
Out of curiosity, what kiln have you actually got?
Quote from: Lee - Kilncare on February 16, 2012, 01:45:38 PM
Out of curiosity, what kiln have you actually got?
Not one of your sadly, I don't want to be accused of slandering another kiln supplier as it's not all bad for the price I paid, but lets just say I bought it two months before you launched the maxi (and been kicking myself for not waiting ever since), and it's similar to that without the brick lining so it's fibre that goes everywhere and doesn't hold the heat so well, a door that jams, a bead guard that I keep slicing my hands on, a controller that broke down....... don't suppose you take part exchange? :D
The only thing I'd say about the pyrometer is it eats through batteries and they are those square do dahs! I get the tesco value ones but I also tend to stick it in the kiln, let it get up to temp and then switch on to see, switch off, leave it a bit then switch on. You get the idea!
It's nice cos it goes up to ceramic temperatures too, so I used it once the temps had gone beyond the KCRs control!
Quote from: Steampunkglass on February 16, 2012, 02:02:47 PM
Quote from: Lee - Kilncare on February 16, 2012, 01:45:38 PM
Out of curiosity, what kiln have you actually got?
Not one of your sadly, I don't want to be accused of slandering another kiln supplier as it's not all bad for the price I paid, but lets just say I bought it two months before you launched the maxi (and been kicking myself for not waiting ever since), and it's similar to that without the brick lining so it's fibre that goes everywhere and doesn't hold the heat so well, a door that jams, a bead guard that I keep slicing my hands on, a controller that broke down....... don't suppose you take part exchange? :D
errrmmm let meee thiiinkk ::) ;D
Oh and I have bone to pick with you, Lee! ;)
That doesn't sound good :-[
I was grilled about how efficient the Beadcube was for fusing in!
I said it's fine as long as you don't want to fuse any bigger than 2cm square pieces! If I'm a remote sales advisor I demand spares! ;)
;D ;D ;D I know who you mean ;D ;D Top girl she though pal.
And is if you are ever gonna be paying top dollar when we need to look after you...TUT ;) :D
Ha ha, one day I'll have the moolah to upgrade my casting toploader, the problem is it's gonna be a custom job to get it through the door I reckon! Or by that point I'll have a bigger space!
What you need to invent is a hover kiln then I can have one floating above Big Blue!
Ah we are back to trying Wingardium Leviosa ;D ;D ;D