High Temp K-probe and Digital Thermometer
- Thread starter Chris623
- Start date
When you start getting that high temp expect to pay some money. Here's a high temp probe from Omega that is rated to 4200F for $386: https://bit.ly/30ZJlBn
It uses a type S thermocouple, type K normally isn't used that high. A bit more reading on high temp probes:
https://www.thermocoupleinfo.com/type-s-thermocouple.htm
It uses a type S thermocouple, type K normally isn't used that high. A bit more reading on high temp probes:
https://www.thermocoupleinfo.com/type-s-thermocouple.htm
springer82
Well-Known Member
Got mine at Omega Engineering. A 1/8" hole an you are good to go.
Chris623
Well-Known Member
Sorry guys, the 3,000 was a typo..............I meant 2,000. I've only three fingers on my left hand which causes a lot of "left-hand" typos. I used to type 90 wpm on a keyboard until the accident, so it's quite frustrating. Anyway..................I'll go to Ed Caffrey's site and see what I can learn. Thanks.
Chris623
Well-Known Member
Thanks, Ken, I looked up Ed's solution. This is for an oven. Clay King ( http://www.clay-king.com/pyrometer.htm ) has a pyrometer with three probes...........two low temp and one high temp...........for $69.88. It's their GM1312 Dual-Input. Looks like a pretty good arrangement to me. I wouldn't have to put anything together or fret about it being wired correctly. I'd be able to monitor both my kiln oven and tempering oven at the same time. Mighty tempted.
Last edited:
Doug Lester
Well-Known Member
If you are talking about monitoring your forge to see if it is up to forge welding temperatures I'd look for a probe that is a bit over 2000°. Maybe 2200°-2300°.
Doug
Doug
The GM1312 should be fine. In my experience, it's an accurate instrument. The downsides to it are that it'll switch itself off automatically after some period and that, because it will work with several different thermocouple types, you need to be sure it's set to the correct one each time.
I have several different pyrometers, including GM1312s, and access to a calibrator. The GM1312s that I have checked against the calibrator have been boringly accurate on all ranges: as good as big-name units at ten times the price.
I didn't have any particular thought when I saw the GM1312 mentioned, except that it's more complicated than it needs to be for the task. I mostly use them with types N and S thermocouples. For type K, I'd usually go for a TM6801 to minimize the chances of making a display selection error. It is type K only and the only choices are degC or degF.
My personal favourite used to be the TM902C with a degC-only display, no auto power off and typeK input only. It was either on and reading correctly, or it was off. No chance of reading it wrong. DegC only is not a problem for me because I think in degC. Obviously YMMV.
I no longer recommend the TM902C because I bought ten of them about 3 years ago and checked them against the calibrator. They were perfect to 800 degC, but then deviated from the input as it rose. I can't honestly remember which way the error went but either the TM902C or the calibrator was reading 1372 degC while the other was reading 1290 degC. All ten were the same. I'd had 20 or 30 TM902Cs previously and all had been accurate over the full range. There were visible differences between the "good" and the "bad" TM902Cs, but they were not obvious without the two instruments side-by-side and would certainly not be visible on an ebay listing.
If using a GM1312, it would be worth looking at typeN thermocouples, as the instrument will accept the input. Type N was developed as an "improved type K": more stable above 1000 degC (1832 degF) and not prone to "drift". I tend to use Mineral Insulated type N in Heat-Treat ovens, where the maximum temperature will not exceed 1300 degC (2372 degF), the upper limit of the type N calibration.
For forge temperature measurement, I usually recommend type K for the extra 72 degC of upper range. I usually USE type S, but only because I have some that I've picked up over the years. They are Platinum-based and painfully expensive to buy new.
I almost always use Mineral Insulated assemblies for types K and N.
I would strongly recommend spending a few minutes with a cup of coffee, a notebook/pen and a telephone talking to one of the technical sales folk at Omega. My (admittedly limited) experience is that they are very knowledgeable and are happy to impart that knowledge. It helps that, because Omega can supply pretty much everything in temperature control, there is little danger of being steered away from the most appropriate solution simply because they don't sell it.
I have several different pyrometers, including GM1312s, and access to a calibrator. The GM1312s that I have checked against the calibrator have been boringly accurate on all ranges: as good as big-name units at ten times the price.
I didn't have any particular thought when I saw the GM1312 mentioned, except that it's more complicated than it needs to be for the task. I mostly use them with types N and S thermocouples. For type K, I'd usually go for a TM6801 to minimize the chances of making a display selection error. It is type K only and the only choices are degC or degF.
My personal favourite used to be the TM902C with a degC-only display, no auto power off and typeK input only. It was either on and reading correctly, or it was off. No chance of reading it wrong. DegC only is not a problem for me because I think in degC. Obviously YMMV.
I no longer recommend the TM902C because I bought ten of them about 3 years ago and checked them against the calibrator. They were perfect to 800 degC, but then deviated from the input as it rose. I can't honestly remember which way the error went but either the TM902C or the calibrator was reading 1372 degC while the other was reading 1290 degC. All ten were the same. I'd had 20 or 30 TM902Cs previously and all had been accurate over the full range. There were visible differences between the "good" and the "bad" TM902Cs, but they were not obvious without the two instruments side-by-side and would certainly not be visible on an ebay listing.
If using a GM1312, it would be worth looking at typeN thermocouples, as the instrument will accept the input. Type N was developed as an "improved type K": more stable above 1000 degC (1832 degF) and not prone to "drift". I tend to use Mineral Insulated type N in Heat-Treat ovens, where the maximum temperature will not exceed 1300 degC (2372 degF), the upper limit of the type N calibration.
For forge temperature measurement, I usually recommend type K for the extra 72 degC of upper range. I usually USE type S, but only because I have some that I've picked up over the years. They are Platinum-based and painfully expensive to buy new.
I almost always use Mineral Insulated assemblies for types K and N.
I would strongly recommend spending a few minutes with a cup of coffee, a notebook/pen and a telephone talking to one of the technical sales folk at Omega. My (admittedly limited) experience is that they are very knowledgeable and are happy to impart that knowledge. It helps that, because Omega can supply pretty much everything in temperature control, there is little danger of being steered away from the most appropriate solution simply because they don't sell it.