Noncontact infrared thermometers?

J. Keeton

J. Keeton

Joined
Nov 15, 2005
Messages
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Does anyone know of a noncontact infrared thermometer that goes up to or past 2500 degrees F? Do they even make them that powerfull? If not how do yall measure the temp inside your forge?

Thanks,
 
As far as I know, there are none. The EXTECH 42545 goes to 1832 deg F, although the accuracy up there is not too good: ±3% +9°F >1000°F...
A thermocouple measuring system is more accurate
 
howiesatwork said:
As far as I know, there are none. The EXTECH 42545 goes to 1832 deg F, although the accuracy up there is not too good: ±3% +9°F >1000°F...
A thermocouple measuring system is more accurate
Click to expand...

Where could I aquire a decently priced thermocouple measuring system?
 
howiesatwork said:
A thermocouple measuring system is more accurate
Click to expand...

That's not necessarily true, I'm afraid. Once you factor in the cold junction reference points, specifications on the TC wire and the thermocouple itself, you are looking at about the same accuracy.

I know that Leeds and Northrop used to make a portable pyrometer that would go past 2500 but they are/were very expensive. L&N makes the Rayotube and Honeywell makes the Radiamatic RH that are both non-contact thermopiles. They too are very expensive but will go well past 2500 degrees.

By the way, Honeywell bought L&N about 10 years ago.

I will check on the TC measuring device I have and will post it here later this evening.

Craig
 
Do they make a none digital thermometer. Kinda like the ones you put in an oven. That goes up to 2500?
 
not sure what you mean....the pryometer sits outside the forge and the thermocouple goes inside. It reads up to 2500 F. They have both a digital and analog version. The analog is considerably cheaper, but less accurate.
 
C L Wilkins said:
That's not necessarily true, I'm afraid. Once you factor in the cold junction reference points, specifications on the TC wire and the thermocouple itself, you are looking at about the same accuracy.

I know that Leeds and Northrop used to make a portable pyrometer that would go past 2500 but they are/were very expensive. L&N makes the Rayotube and Honeywell makes the Radiamatic RH that are both non-contact thermopiles. They too are very expensive but will go well past 2500 degrees.

By the way, Honeywell bought L&N about 10 years ago.

I will check on the TC measuring device I have and will post it here later this evening.

Craig
Click to expand...
I got carried away this morning...
Yes, the L&N and Honeywell optical pyrometers you mention are very accurate, and very expensive.
Temperature in a forge, in the sizes used by knifemakers, can be difficult to measure.
A electric kiln would be much earier to measure, as there are less variables affecting the measurement, seeing as the door can be closed, and the temperature variations smoother than a gas forge.
A gas forge has much going on in it... flame temperature is much higher than the contents, the linings are heated, and also a radiating heat source when up to temperature, and then there is the open ends where the gases must flow out to keep this all going... Confusing enough?
Not yet... The steel you have sitting in the circulating flow is likely to exceed the temperature of the lining, as it's in the circulating gas source heat.
Now, back to measuring it...Can you look through the door in a forge to see the steel? Yes.
If you are using an optical method to measure the temperature of the steel through the door opening, are you seeing the temperature of the steel, or are the hot exhaust gases coming out through that door going to skew the measurement?
I think so, and this is why I would measure the inside temps with thermocouples.
K thermocouples is the way I go, with a process controller.
 
I purchased a used Minolta-Land Cyclops 53 noncontact infrared thermometer on Ebay earlier this year. It has an operating range of 1100 to 55oo degrees F
I also purchased a Whal Model TM-500 K-type thermocouple thermometer, which will measure up to 2498 degrees F. I need to use the thermocouple thermometer to calibrate the Infrared thermometer for varying lighting conditions. Hope this helps.
 
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