PMEL Forum

While I'm on a small posting binge, thought I'd share generalities of some temperature work I did a few years ago (I won't share everything, as I hope to patent it in the next few years). . . .


While working in a Fortune 100 facility, using freeze point cells (very accurate), I did some long term experiments on Type R thermocouples.   I kept them exposed to very high temperatures (>1000 Deg C) 'soaking' for more than a month.   At regular intervals, I replaced them in Copper, Aluminum and Zinc freeze point cells and measured their mV/Deg C characteristics.   I had 16 thermocouples, and accumulated a few thousand data points.

I found some surprising things (that when I emailed someone at NIST, they were even interested in it).   There was a stable, predictable change over time of the mV/Deg C characteristics of the thermocouples.

Now, why do I think this is significant?  Some industries require very high accuracies at high temperatures.   If I can use my prediction curve (this is some of what I won't share here) to plot mV/Deg C drift over time based on how the thermocouples are used, it may improve their usable accuracy.

Why am I posting this here (besides my "posting binge")?  I want to pass this by you metrology types to see if anyone has any thoughts or ideas on how marketable this may be, or who I could market it to.

P. S.  - Shameless plug for the other forum I am co-moderator of www.elsmar.com , then go to the calibration and ISO17025 section.   It is non-commercial, so no financial implications.   I really enjoy this forum, as it leans more toward the technical side of metrology, where the other leans toward quality standards.

If anyone has thoughts or questions about thermocouple stuff above, feel free to email me.

I can see some applications in the testing area, primarily with enviromental testing chambers. What I have gotten from our lab techs is a problem with tolerances on some ASTM and UL standards. I don't remember all the particulars of the standards, but seem to recall something about the standard requiring the equipment being 2 1/2 times better than anything being built currently.