stevieturbo wrote: ↑Wed Dec 18, 2019 11:26 pm
Good video, I had asked many times before...how do we actually test or calibrate thermocouples, rather than just hoping they read correctly.
I'd seen other people claim they are very fast...errr nope, they arent, by design they cant be
Yeah its not that hard to do a valid test.
I guess either,
A) Response: 'they' have done the test and don't want to disclose the real truth as who else would take the time to disprove or otherwise contradict them?
B) Accuracy: bombard you with the std replies of once its stabilized they all read the same (which they do not)
Through my own research on this I did find some published papers which describe the effect of where the voltage is generated in the TC, and its not at the tip/junction rather a way down further from the saturated point (which by color indicates the same temp give or take). In short without boring people too much at/near the measurement zone (from my own work) its the thermal mass of the probe, the wire used to make it, the insulation, and other factors I wont go into that dictate the accuracy once the probe is saturated (ROC = 0).
The size's, materials, and manufacturing details I finally selected were tested to strike the best balance of durability, response, and accuracy.
How to use an EGT probe is a whole other topic
can they be fast? you bet! just need one design right