Pyrometer?

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Arnak

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Hi Folks,

I am considering getting a Pyrometer to use for tempering steel but I am not sure if the infra-red types are the way to go.:confused:

Could someone advise me please?

Martin
 
Hi Brian,

Souns like just what I need, thanks for the info.:D

Martin
 
Be careful of the readings on these, they measure reflected IR and can be easily fooled. As an example I have used them to measure the temperature of hot water pipes on my boiler. As I scan along the pipe the reading will jump a lot when I pass over a section that has solder wiped on it. Clearly the pipe is all at the same temperature, but the reflective solder gives a much different reading. I have also seen this on things like a cast iron cylinder block, with different readings on painted spots over bare metal.
 
The issue I have found is the IR units do not go above 1000F, way to low to be usable for Curie point which is 1400+. And the point where you harden the material is more important than the point where you draw(temper) the material.

If you miss on the curie point, any drawing is for naught.
 
I have a really expensive IR unit (around $700 I think it was - I didn't have to pay for it) left over from my bearing industry days. Not sure what the max temp is from memory, but it has adjustable emmisivity for calibrating to correct temp based on the surface being tested. Unfortunately you have to know what the emmisivity acutally is of the surface.

Doing a side by side comparison with the cheap IR guns, they can vary wildly from actual temp due to different surfaces and substances. They do come in really handy when cooking food though and I keep a cheap one in the kitchen all the time.
 
Gus will fall back on the good old temperature gaging by eye-ball. Most accurate at night. The Japanese Katana SwordSmiths still use it today and none has ever gone using digital.

Caution: Only good for carbon steel hardening and tempering.

I did have an electric oven to heat treat treat tool steel. With this oven I heat treated many press tools. ASSAB Steels was my favourite.
 
I second what gus says. It is a very useful skill to be able to judge heat ranges for metalworking by color. I also like judging heat this way because you can also see if your heat is even throughout your workpiece. I do the high-heat metal things outdoors and find dusk is a good time to do these things.

--ShopShoe
 
I second what gus says. It is a very useful skill to be able to judge heat ranges for metalworking by color. I also like judging heat this way because you can also see if your heat is even throughout your workpiece. I do the high-heat metal things outdoors and find dusk is a good time to do these things.

--ShopShoe

Hi Shop Shoe,

Thanks for sharing. Hardening and tempering the good old fashion way is not hard to pickup. Just read an article. Oil Hardening has its secrets. I have used Quenching Oil with some success. Fast Medium and Slow Oil for tool steels. Used engine oil is dicy but better than veggie oil.
 
Came across an article on heat treatement of steel using the old fashion methods but slightly updated. Please get a copy of Model Engineers' Workshop No.225 Feb 2015 and read up Richard Rex's article-------------Heat Treating O1 & W1 Tool Steels page 17.
Attached fotos will give a good idea on heat treatment of steel w/o the expensive Pyrometer.
The Baking Temperature is very cost effective. I plan to buy same oven and temperature gage which will be hopefully not M.I.C. aka Made in China. The Oven most likely M.I.C.;):rant:

IMG_2835.jpg


IMG_2834.jpg


IMG_2836.jpg
 
When I bought my pyrometer, I wasn't even thinking about heat treat temperatures. I bought it to monitor the temperature that my air cooled i.c. engines run at.
 
Technology has advanced so far/fast since 80s when I attended Explosion Proof Electric Motors and Starters Training Course. A fellow attendee was moonshining and trying sell his very expensive Non-contact IR Pyrometer which cost US$3000 to Gus to read Aluminum Melt/Pour Temperature. Was advised by another attendee,the reflection of the the melt surface could render temperature reading inaccurate. So I stucked on using the old fashion US$80 USA made Thermocouple Temperature Gage and continued casting/pouring Aluminum at the best temperature. Pouring temperature is important to avoid excessive shrinkage or cold runs in C.I.Molds. So many scraps to pin point best pouring temperature. C.I.Mold temperature was easy to spot but same heats up, you kind let same cool down a wee bit. Usually recharging furnace with fresh ingots help kill time.
 
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:) I will go with something more like 800 C or 850 C.
 
The issue I have found is the IR units do not go above 1000F, ...

I have an IR unit that goes to 1650C (3000F). Purchased on e-bay in the past year, unfortunately the unit has no make/model or manual. Cost was not much more than the very common ones with the 1000F limit.
 
I use out a foundry goes up to 2500 F [1370 c] works great
Dave

I have an IR unit that goes to 1650C (3000F). Purchased on e-bay in the past year, unfortunately the unit has no make/model or manual. Cost was not much more than the very common ones with the 1000F limit.
 
Plan to get serious with heat treatment. Todate I have not done tempering at all. Bought M.I.C. Baking Temperature Gage 100F--------500F. Will buy a small Oven too.Best to refrain incurring the wifey boss's oven and incurr her wrath. With Temperature Gage,I will try out tempering DIY Cutting Tools such as counterbores,gear hobs and reamers etc . I admit this is the old fashion way but proven by quite a few DIY heat treaters. I have 2 DIY counterbores to temper.

IMG_3584.jpg
 
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looks like 700 to 750 c to me :) Thats furnace temp,not element temp.
 

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