Neycraft Kiln Pyrometer off

I have this neycraft kiln that i use mainly for casting jewelry pcs. The other day i had 4 blades profiled and ready to heat treat. Couple of band saw blades and some 1095. First heat up to 1450 and quench into parks 50. Clean them up check for hardness. File bites and i can bend the thin band saw blades and the do not flex back. Put them in again since the kiln is hot bring up to 1500 and quench. Same thing! Flustered i called Bubba-san and we came to the conclusion that it must not be getting hot enough. Try a magnet he says. Good idea!Crank it up to 1500 pull it out magnet sticks. Go to 1550 same thing. 1600 bingo! No stick. Quench and hardness. I was unable to grasp at first that the pyrometer could be wrong and that just a few degrees would make that much difference.Something as simple as a magnet confirmed that it was off. A great learning experience.
Doug

Doug,

What your plan of action for calibration ?

New Thermocouple ?

New PID?

Some type of programming fix ?

Inquiring minds want to know

-Josh

Bunch of new magnets , its a lot cheaper :biggrin:

Sell it and get a new oven with a controller so i dont have to manually change it every couple hours? Just keep in mind that its off 150 degrees or so. Not so critical for casting burnout. I will look into any other options.

I also use a Neycraft oven. I have a controller for it, but it is still off a few degrees when measured with a digital pyrometer (?). I marked the furnace adjustment knob with the actual temperatures and don't go by the numbers on the dial.

I think it important to recognize that its fairly common for the top of a kiln - where the thermouple usually is - to be as much as 40 degrees hotter than the blade rack at the the bottom. This will likely hold even after an hour or more to let the temps stabilize. 40F can be a lot.

An external pyrometer with a long probe can give lots of insight.

I have a Neycraft oven also . Its a few degrees off even when it on and heated up . I dont have a lot of faith in electronic temperature probe s
I have 3 of them and they all read differently . If I am am h'ting small blades I always double check them with magnets . Magnets will not fail you when trying to reach critical temp . Heat and electronics do not compliment each other very well. Metalurgy is not an exact science . So I try and supplement with common sense and a few magnets ....

I here you Bubba. I have seen were Josh has elevated his knives up next to the temp. probe to get a more even reading. Thats a good idea also.

Hey Doug , your blades are getting better everytime I see one , I really liked those band saw knives . Your engraving is tops as far as I am concerned . We need to make some more Japanese blade parts , your castings are very good and I look forward to doing some more of them.
Bubba

Thanks Bubba, I finally feel like i know what i am doing with the knives. Casting and engraving are my stong points. Some day i hope to put everything together.
Thanks knifemaker CA. That was ceartinly the case with mine kiln.