pyrometer digital or IR

[jdale]

Desperately needing to buy a pyrometer but i dont know weather to buy a digital probe pyrometer or a infrared one. Would i want to know the temp of the forge interior, or use a IR one tocheck the temp of the steel itself? Are the IR pyrometers as accurate as the probe version?

[Doug Lester]

The biggest thing to check on is range of operation. A lot, possibly most, of the infrared pyrometers are not accurate at the ranges that we operate with. I remember a gun show where they measured a glowing red gas tube on a rifle and came up with something like 800-850 degrees when steel glows red at closer to 1500-1600 degrees. They were just trying to get their unit to operate in ranges it was not built for. I understand that there are infrared pyrometers that will measure in the ranges that we work with, though I have not seen one advertised. My feeling is that they are special use industrial units the really put the expense in expensive.

On the digital, or even analog ones, they often come with probes, the thermocouple, that are also not rated for the temperatures we deal with. I did see some on Amazon that came with thermocouples that were certified up to 1800-2000 degrees. That would work for regulating the forge for heat treating but it won't cover you if you want to tell that the forge is up to welding temperatures. Also, and I have one, there are units that for some reason won't display reading of 2000 degrees or higher. I can watch mine heat up and go from 1999 degrees and then display 1 degree and stay there until it cools. I'm either going to have to get a unit that measures over 2000 degrees or just learn to go by color for forge welding if I get into it more.

Actually the best place I've found to get ceramic shielded thermocouples that will operate/survive at temperatures over 2000 degrees is Ebay. You might even find a seller that pairs one with a pyrometer that will register over 2000 degrees too. Another place to look for both would be a dealer that sells pottery and/or glass kilns. They too deal in equipment the operates in those temperature ranges.

Doug

[EdStreet]

DIY Pyrometer

[Doug Lester]

I clicked on the link and you can do better on Amazon and possibly Ebay with no assembly required if you aren't going to be dealing with welding temperatures. You may well be able to do better with one of the commercially available pyrometers through Amazon even if you have to go to Ebay to get a ceramic shielded thermocouple that will stand up to welding temperatures. The advantage of the unit featured in your link is that it can be used to operate a solinoid or a heating element.

Doug

[EdStreet]

It's always good to make your own tools

I found a few meters around $150 and IR's bit more than that. This project I did has some very good potential for many other areas and give results/uses that a commercial unit will not be able to provide, i.e. expanded use in controllers. I do plan on expanding this project to include things in that areas eventually.

[Doug Lester]

If you get satisfaction from making your own tools, fine, but it is only good if you make them correctly. I've had a couple of forges in my history that, let's just say, they weren't all they could be and the money that I spent on them were wasted. Some things, like presses are ok if you already have the tools and skills that you need to construct them or you will be better off to buy a ready made unit. It doesn't take many mistakes for your money saving efforts to be very expensive.

I think that J. just wants to know how hot his forge is running. I just ordered duel channel pyrometer for $21.99 and a ceramic shielded thermocouple for $19.99, both can operatie at 2300 degrees that would do just that. Granted, I did find several PID controlers that didn't run much more than the pyrometer but you would still have to find a thermocouple that would operate at 2300 degrees. All I'm going to have to do when the units get in is to switch out the thermocouple on the pyrometer and attach the one that I already have to it. No wiring to try to figure out. Just plug and play.

Doug

[jdale]

I ended up getting a 2000? digital pyrometer and a thermocouple rated at 2300? with shipping for $60. I didnt see the point of ordering one for monitoring forging temps as i am years from making Damascus