No I am not offering a job.
There have to be some Heat Engineers who do this Calculation for checking the Accuracy of Heat Flow Meters.
IT is given at Annexure 2 of ASTM C518 under EQ. 2.2.
Thanks
Somebody has definitely misunderstood something.
Either the OP hasn't understood that a discussion group like this is for people who help others to accomplish something for themselves, or...
Or member IRStuff didn't understand that you need to get this work done quickly and he'd better hurry up with the answer for you.
Well, instead of arguing about that, perhaps a more direct question is in order:
rkvbobby123, why aren't you doing the calculation yourself if you know what needs to be done?
I don't know what is there to misunderstand. It was just an innocent query if someone has done those calculations and looked ar this annexure 2.2 under ASTM C518.
If not, not an issue. We just learn from each other. Basically, these Cals relate to finding R-Value of any insulation and I was looking at other folks work in this area.
The interacting Factors, S, L,E and Delta T have usual meanings given in the standard and equation is well spelled out there.
Thanks anyway.
I have this with me, infact lots of folks know him well.
Looking below then, could you interpret this table. I understand those percentages but how do we arrive there. We are comparing different materials I can see.
Thanks.
TABLE II. SINGLE-THICKNESS TESTS VS. SINGLE-THICKNESS
CALIBRATIONS
Tests Pyroceram® Pyrex® Vespel® Perspex®
6.35 6.60 6.18 5.00 mm
UP 63031 31618 14123 9505 V
LP -61795 -31012 -13797 -9242 V
Ref.values Calibrations
(W/mK) 6.35 mm X 2.091 0.875 0.476 W/mK
63031 V X 2.092 0.872 0.472 W/mK
-61795 V X 2.092 0.873 0.474 W/mK
4.011 Pyroceram® X 91.2 134.1 150.8 %
6.45 mm 2.15 X 0.468 0.255 W/mK
31618 V 2.15 X 0.466 0.253 W/mK
-31012 V 2.15 X 0.467 0.254 W/mK
I tried to separate the numbers but it shows up like this again.
But Briefly, we are comparing four types.
My question was having calibrated with a atandard SRM, how does the mV reading play into the Final R-Value.
I know how to calculate Calibration Factor. How does it come in the picture.
63000 Micro Volts and W/mk and R-Value are related.
Thanks.
Have a great Thanksgiving.
No, uV has to do with the thermocouple reading. It's only relevant to the extent that it was what they used to make the temperature measurement. Had they used a PRT, would uV still be meaningful?
TTFN
faq731-376
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Of course I can. I can do anything. I can do absolutely anything. I'm an expert!
The Calibration factor for a NIST SRM say is 1.2, atleast that was the case in my test.
The Same material of equal thickness should come close to this number.
If the material is of a different make than that of the SRM or of a different thickness, should the Calibration factor change or stay the same. What is the signidicance of Calibration factor apart from assuring the HFM is performing as it should.
I would appreciate if some Hand written cals are shown. I am of the Old School.
Uncertainty of any measurements is the RMS of the systematic and random uncertainties. say Utotal = RMS (Us^2 + Ur^2)
Systematic uncertainty is the sum of the all systematic uncertainties of the measurement including amongst other things the calibration uncertainty.
The calibration uncertainty is related to the correlation coefficient R2 of your linear regression or your linear fit (if it is linear).
Random uncertainty is basically linked to the number of measurements that at the end you average for a given sampling rate.
I dont know if that helps..
"If you want to acquire a knowledge or skill, read a book and practice the skill".
