On Tue, 14 Dec 2010 01:06:39 -0800, the renowned Robert Baer
wrote:

With regard to Minco, nope!
GOTO http://www.minco.com/tools/sensorcalc/rtd/default.aspx

Yes, that refers to the Callendar-Van Dusen equation. Did you look up
what the Callendar-Van Dusen equation actually *is*?

Sign up and get their white paper as their catalog suggests. It's all
in the

"Resistance Thermometry: Principles and Applications of Resistance
Thermometers and Thermistors"

In that white paper, PDF page 4, the table shows the two equations for
the two temperature ranges.

Selecting element code PE Platinum 100 ohms at 0°C 0.00385 Nominal
IEC curve but looser tolerance (5-100):
Equation Type: Callendar Van-Dusen
Standard Values
A 0.0039083
B -5.775E-07
C -4.183E-12 ----*

And, at the top of the table, no matter what valid range you give, is:
Temperature Vs. Resistance
PLATINUM : PE TCR = 3.85e-3

R0 = 100

A = 0.0039083 B = -5.775E-07 C = -4.183E-12

This info was transfered via cut and paste.
I did not bother to look at your other "references", as Minco clearly
makes no indication like what you stated.



Honeywell: NOPE! See page three of their PDF at
http://content.honeywell.com/sensing...log/c15_89.pdf
No indication of the buggered equation you gave; just the same
equation that Minco gives.

Don't know how you missed this: "Both beta = 0 and C = 0 for T0°C"
right under the chart.

**
Keithey: Found only info with regard to their equipment measuring
RTDs or have/use RTDs but NO INFO on RTD curves; I give that reference a
SORRY, no tuna tonight!

http://www.keithley.com/data?asset=4440

PDF page 5.
For T0°C, the b term can be ignored and the equation becomes
quadratic


**
TI: Similar lack of direct RTD data info, only instrumentation; I
also give that reference a SORRY, no tuna tonight!

"
http://www.analogzone.com/acqt_052807.pdf
Top of the second page (PDF doesn't allow copying)


**
Sorry! Give direct references that all can see!

Above are four, but also:
http://forums.labjack.com/index.php?showtopic=1273
"C = -4.183 E -12 (below 0 C), or
C = 0 (above 0 C)"

and this one, which someone else already gave:

http://en.wikipedia.org/wiki/Resistance_thermometers

(the two equations are given under "Standard resistance thermometer
data"

And this
http://www.uniteksys.com/Graphics/CalVan.pdf

And this (NI)
http://newton.ex.ac.uk/teaching/CDHW/Sensors/an046.pdf
" For temperatures below 0° C only; C = 0.0 for temperatures above 0°
C."


Crikey. Are EIGHT correct references insufficient to convince you?


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com