[USMA:48457] Re: kelvin

[mechtly]

Correction:

The quotation below on calibration contained only the letters "CCT", not the 
full name of the CCT which is the "Consultative Committee on Thermometry" (not 
"on Temperature" which I had incorrectly identified.)

-- Original message ----
>Date: Wed,  1 Sep 2010 17:34:14 -0500 (CDT)
>From: <mech...@illinois.edu>  
>Subject: [USMA:48456] Re: kelvin  
>To: "U.S. Metric Association" <usma@colostate.edu>
>
>
>My source of information on questions of temperature is NIST Technical Note 
>1265; Guidelines for Realizing the International Temperature Scale of 1990 
>(ITS-90), by B.W. Mangum and G. T. Furukawa, August 1990.
>
>The fixed points of the ITS-90 are Freezing Points, Melting Points, Boiling 
>Points, or Triple Points of various substances; atoms or molecules. More than 
>twenty seven are included.
>
>With respect to calibration: "The ITS-90 was designed by the Consultative 
>Committee on Temperature (CCT) in such a manner that temperature values 
>obtained on it do not deviate from the kelvin thermodynamic temperature values 
>by more than the uncertainties of the latter values at the time the ITS-90 was 
>adopted."  "The size of the kelvin is defined to be 1/273.16 of the 
>thermodynamic temperature of the triple point of water."
>
>t/(deg C) = T/K - 273.15;  defines thermodynamic temperatures in Celsius.
>
>t(subscript 90) denotes ITS-90 temperatures also in Celsius.
>
>The "International Practical Temperature Scale" IPTS-of 1968 (amended in 
>1975). has been formally abrogated.
>
>t and t(subscript 90) are not the same.