I was wondering if anyone on the forum has ever annealed a PRT? Does it really make a difference? Hart Scientific says it does. I am annealing one now in my furnace. What should I expect to see? I have a PRT with a history of 100.025 ohm @ TPW and now it's 99.917 Ohm @ TPW. Will annealing help or am I wasting my time? I am supposed to go the Hart for school, but I want to know now. So who can help? :?
Yes it can help...................is it used at high temps constantly??? If no, then I would say it is another problem.
Also be careful with those furnaces........................I've seen more than one imitating the leaning tower of pisa
From the looks of the PRT I don't think they use it at high temps. However, Hart claims that physically damaged PRTs can be corrected by annealing. I will drop it in my TPW cell tomorrow and I will let you know how it turns out.
That is almost a shift of 0.28 degreesC
Yeah, I don't expect much, but I need to cover my but when I notify the customer that their PRT is bad.
It's actually a 0.108 shift. Even still i don't see it changing that much from annealing it. With that kind of drift I will have to reject it. Unless a miracle happens during the annealing process.
Quote from: flew-da-coup on 04-26-2006 -- 11:26:38
It's actually a 0.108 shift. Even still i don't see it changing that much from annealing it. With that kind of drift I will have to reject it. Unless a miracle happens during the annealing process.
Yeah I was using a 100 ohm curve.
I don't see that working for it either.....but hey ya never know
Here is what Hart says:
First, during the course of normal use, an SPRT is subjected to mechanical shock, which induces strain in the sensor wire resulting in a change in resistance. Mechanical shock can be incurred by the slightest tap to the SPRT sensor while inserting or removing it from an instrument. Vibration during transport can also be a cause of mechanical shock. The SPRT is an extremely delicate instrument. Even with great care, mechanical shock can be introduced causing a significant change in resistance. Annealing the SPRT at 660°C for one hour can eliminate most of the strains caused by minor shocks and restore the resistance close to its original value. Annealing is always advisable after any transport of an SPRT. 2
Holy crap MIRCS. it worked. 1 hour in the furnace @ 660 Deg.C. Brought my TPW to 100.023 Ohms. I guess i have to take my hat off to the guys at Hart. They really know their crap.
Quote from: flew-da-coup on 04-26-2006 -- 13:16:53
Holy crap MIRCS. it worked. 1 hour in the furnace @ 660 Deg.C. Brought my TPW to 100.023 Ohms. I guess i have to take my hat off to the guys at Hart. They really know their crap.
That's why I love Hart...........they know their crap inside and out on temperature. I never thought that would work
Well I guess we both learned something. I checked the TPW this morning and it's still good. Hart recommends annealing after shipping the PRT as well. Check out Hart's artical on annealing on their website. I learned alot. I can't wait to go to school out there.