Contemplating a pyrometer

Stacy, which HF thermometer are you using? I didn't think the $15 would read up to forging temps. Thanks in advance, you may be saving me some moneys :)
 
Stacy, Did you ever try hitting the blade with your laser IR pyrometer immediately after pulling it out of the forge? Wouldn't the IR unit work effectively then? I mean, say you're going to oil quench W2. You're losing a second or two from the time that you remove the blade from the forge and put it into the oil, right? So, wouldn't the same line of reasoning hold for getting a temp right off the blade immediately after pulling it from the forge?
Thanks
- Mitch
 
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I have seen Ariel Salavera (sorry if I botched the name) point his laser thermometer straight into the forge in some of his tutorials. I have wondered if this is very accurate due to the high intensity of the radiant light that forges emit, but he definitely knows what he's doing.
 
Troop said:
Stacy, Did you ever try hitting the blade with your laser IR pyrometer immediately after pulling it out of the forge? Wouldn't the IR unit work effectively then? I mean, say you're going to oil quench W2. You're losing a second or two from the time that you remove the blade from the forge and put it into the oil, right? So, wouldn't the same line of reasoning hold for getting a temp right off the blade immediately after pulling it from the forge?
Thanks
- Mitch
Click to expand...

Good point.
 
Taking the temperature of the blade outside the forge will only tell you what temperature it is at that moment. It won't tell you if it has been in a forge that is too hot. The better alternative is to monitor the forge chamber temperature and not let the blade be in an atmosphere that will harm it. It can sit for two minutes or ten, as long as the temperature is no higher than the austinitization target, it won't harm the blade.

Most laser guns won't read accurately aimed at a flame. You can adjust the emissivity setting and compensate for it somewhat, but every time it may be different.
Stacy
 
On the same subject as a forge that's too hot. Does anyone use any type of O2 sensor?

My current forge can be set for constant temperature during the soak and the blade will not build any scale. The environment appears to be pretty stable and void of O2. In fact, the scale only forms when I remove the steel for a few seconds, and that amount is paper thin - which I am kind of proud of.
 
I have a thermocouple from a pottery kiln, what is the HF thermometer?
I lloke at their site but did not see anything that looked like it would go with what I got. Cheers Ron.
 
The HF unit is a 2000F digital thermometer. They do not always carry it, and it is often not listed. Check with your local HF and see if they have one on hand. A PID works just as well.

Here is the same unit on ebay for $20.
http://cgi.ebay.com/2-K-Type-Digita...5|66:2|65:12|39:1|240:1318|301:0|293:1|294:50

Here is a search for type K thermometers:
http://shop.ebay.com/items/?_nkw=di...270.l1313&_odkw=digital+thermometer&_osacat=0

This is the type of probe you want:
http://cgi.ebay.com/Thermocouple-K-...5|66:2|65:12|39:1|240:1318|301:1|293:1|294:50

Stacy
 
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bladsmth said:
Taking the temperature of the blade outside the forge will only tell you what temperature it is at that moment. It won't tell you if it has been in a forge that is too hot. The better alternative is to monitor the forge chamber temperature and not let the blade be in an atmosphere that will harm it. It can sit for two minutes or ten, as long as the temperature is no higher than the austinitization target, it won't harm the blade.

Most laser guns won't read accurately aimed at a flame. You can adjust the emissivity setting and compensate for it somewhat, but every time it may be different.
Stacy
Click to expand...

Stacy, I see what you're saying, and I agree with you about the point that you're making. Why not just monitor the environment of the forge chamber. Absolutely agree.
But, just as an alternative, (and if someone just dropped $ 199.00 on one :)) if I'm hitting the blade with the IR pyrometer immediately as I pull it from the forge, it will be darn close to what the temperature of the blade was while inside the forge.
Thanks for your reply.
- Mitch
 
Well, Stacy was right, once again.
I got my laser IR pyrometer today, and the readings of my forge with the burners on produced extremely erratic readings, and blanking-out the reading entirely when I hit the flame itself with the laser.

Good thing I backed myself up with this stuff from Omega:
http://www.omega.com/ppt/pptsc.asp?ref=HH500
I wound up getting the HH502. I didn't need such a high priced unit, but I figure it will last me a while. $ 109.00
I got this Omega-clad K-type probe as well, 0.25" thick...that should last a while.
http://www.omega.com/ppt/pptsc.asp?ref=TJ36CAXL_NNXL $ 38.00

It was really easy to set up; I just drilled a 1/4" hole into the side of my forge, stuck the probe through the hole and through the kao wool, hooked the probe up to the gizmo, and that's it! The probe stays in all by itself because of the snug fit.
It works great!

See, I follow you guys' advise....once in a while.:)

With the above items, you need to buy a dinky little $ 1.75 connector.
http://www.omega.com/ppt/FindPN.html?seek=SMPW-KM&searchbyp=yes
Part # SMPW-K-M

- Mitch
 
Sorry about the IR laser, Troop. It will be handy for things like checking the quench tank temp, the tempering oven, and salt pots.
The probe and meter system for reading the forge temps is a reliable system, but just like the IR laser, it can be reading the flame not the actual chamber temp if it is not placed properly. This is one of the best reasons to make the forge run as a two-stage controlled forge.
Stacy
 
I have a mac tools EM 720 multimeter, with a -4 to 2498F temp range, but I need an adapter to plug the k type thermocouples into it.... wich is damn near the same price as one of these things... pluss it might not be such a smart idea to have a $200+ peice of plastic near my forge. it came with a temperature sensor, but its only a small wire thing, and it does go up to the temp I need but its not going to last very long lol.
 
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