James R. Frysinger
Sat, 04 Sep 2010 16:48:35 -0700
The triple point for water is hard to reproduce with precision as well. It is highly dependent on isotope ratios and ionic content. I would imagine that leachates from the glass cell are a problem.
This difficulty is one reason that a new definition for the kelvin is being sought.
Jim On 2010-09-04 1822, John M. Steele wrote:
The steam point is a TERRIBLE fundamental standard because it is quite pressure dependent. That pressure dependence is the basis of: *Steam Tables (and steam engines) *Pressure cookers *High altitude instructions in cooking Even the melting point is slightly pressure dependent. Under the modern definitions, even at standard pressure the melting and boiling points are not PRECISELY 0°C and 100 °C. ------------------------------------------------------------------------ *From:* Brij Bhushan Vij <metric...@hotmail.com> *To:* U.S. Metric Association <usma@colostate.edu> *Sent:* Sat, September 4, 2010 1:41:31 PM *Subject:* [USMA:48463] Universal Teperature Scale (*UT) RE: Re: kelvin Sirs: It is not my desire to confuse the 'kelvin Tempertaure Scale (*º*K)' or the new emerging need for its revision. However, I pointed a method to resolve */"Negative Temperatures" in 1982, /*if and when the need to re-consideration of defining KELVIN - the thermodynamic temperature scale, arose. KELVIN was accepted at 13th CGPM (1967) as the unit for thermodynamic temperature - as the fraction 1/273.16 at tripple point of water. I placed the 'idea of extending' the thermodynamic scale between *Absolute Zero (-273.16ºC) and Steam Point (100.00**ºC), *thus making each 100-graduation as 1-degree Universal Temperature Scale i.e. 1-UT =(273.16+100) div.100 =3.7316*K. This idea had been placed between pages 87 thro 90 in my book Towards A Unified Technology (1982) among the Chapter SI UNITS - REDEFINED (pages 72 thro 95). Brij Bhushan Vij (MJD 55443)/1726+D-244W36-06 (G. Saturday, 2010 September 04H13:69 (decimal) EST Aa Nau Bhadra Kritvo Yantu Vishwatah -Rg Veda The Astronomical Poem (revised number of days in any month) "30 days has July,September, April, June, November and December all the rest have 31 except February which has 29 except on years divisible evenly by 4; except when YEAR divisible by 128 and 3200 - as long as you remember that "October (meaning 8) is the 10th month; and December (meaning 10) is the 12th BUT has 30 days & ONE OUTSIDE of calendar-format" Jan:31; Feb:29; Mar:31; Apr:30; May:31; Jun:30 Jul:30; Aug:31; Sep:30; Oct:31; Nov:30; Dec:30 (365th day of Year is World Day) ******As per Kali V-GRhymeCalendaar***** "Koi bhi cheshtha vayarth nahin hoti, purshaarth karne mein hai" My Profile - http://www.brijvij.com/bbv_2col-vipBrief.pdf Author had NO interaction with The World Calendar Association except via Media & Organisations to who I contributed for A Possible World Calendar, since 1971. HOME PAGE: http://www.brijvij.com/ Contact via E-mail: metric...@hotmail.com ------------------------------------------------------------------------ Date: Sat, 4 Sep 2010 04:39:37 -0700 From: jmsteele9...@sbcglobal.net Subject: [USMA:48462] Re: kelvin To: usma@colostate.edu I was also a bit confused on this, as well as thermodynamic temperature vs the ITS-90 practical temperature scale. The first link is from our friend Anthony O'Conner. I am aware many people have set him to "ignore," but the article is worth a read. The second is a follow-on link from the first on ITS-90. The two, taken together, clarified things a bit for me. http://www.nature.com/news/2009/170609/full/459902a.html http://www.nature.com/news/2009/170609/full/459902a/box/1.html ------------------------------------------------------------------------ *From:* "mech...@illinois.edu" <mech...@illinois.edu> *To:* U.S. Metric Association <usma@colostate.edu> *Sent:* Fri, September 3, 2010 12:04:56 AM *Subject:* [USMA:48460] Re: kelvin The triple point of water is the temperature at which the solid, liquid, and gas phases of isotopically natural water are in equilibrium. This temperature is the single fixed point of the "kelvin thermodynamic temperature scale"; defined numerically to be 273.16 kelvins. How can Boltzmann's constant be used to improve this scale? Where can we read the proposal for the 2011 CGPM meeting? ---- Original message ---- >Date: Thu, 2 Sep 2010 20:41:10 +0100 >From: "Martin Vlietstra" <vliets...@btinternet.com <mailto:vliets...@btinternet.com>> >Subject: RE: [USMA:48457] Re: kelvin >To: <mech...@illinois.edu <mailto:mech...@illinois.edu>>, "'U.S. Metric Association'" <usma@colostate.edu <mailto:usma@colostate.edu>> > >There is of course talk of a proposal to redefine the temperature scale at >the 2011 meeting of the CGPM by defining the value of Boltzmann's constant >and using that definition to derive the triple point of water etc.
-- James R. Frysinger 632 Stony Point Mountain Road Doyle, TN 38559-3030 (C) 931.212.0267 (H) 931.657.3107 (F) 931.657.3108