Talk:Standard temperature and pressure

message: perhaps some applications of calculations at these two temps could be discussed.  if i recall correctly, STP is used for most gas calculations (e.g. PV=nRT) and SATP is used for thermodynamic calculations (e.g. free energy).  Bubbachuck 14:53, 3 August 2005 (UTC)
thread_title:  0<sup>o</sup>C vs. 25<sup>o</sup>C 

message: In this page it's said: 
"In chemistry, the term standard temperature and pressure (abbreviated STP) denotes an exact reference temperature of 0°C (273.15 K) and pressure of 1 atm (defined as 101325 Pa)."
But in this page:
http://goldbook.iupac.org/goldbook/S06036.html
I read that it's 105 Pa instead of 1 atm:
"STP Abbreviation for standard temperature (273.15 K or 0 °C)
and pressure (105 Pa); usually employed in reporting gas volumes."
:I think the 105 Pa is only a (very rough) approximation. Eric119 04:55, May 8, 2004 (UTC)
http://goldbook.iupac.org/goldbook/S05910.html provides a partial explanation. Rich Farmbrough 20:14, 5 Oct 2004 (UTC)
thread_title:  101325 Pa vs. 10<sup>5</sup> Pa 

message: i have moved that here:
The Army Standard Metro atmosphere, now used only in ballistics, defines sea-level conditions as 750.000 mmHg of pressure (29.5275 inHg, 99.9918 kPa), 59 °F (15 °C), and 78% humidity. (Ref: U.S. Army Ballistic Research Laboratory, U.S. Army Aberdeen Proving Ground)
as Wikipedia is a international project any National Std should not been given prefference, perhaps if some wants to introduce, he should make a page of US or US mil std....
(Wilhelm.peter 14:23, 8 September 2005 (UTC)
replies: text: Whether or not it is a national standard (and I doubt that this one is) is irrelevant, it isn't a matter of giving preference, it is one of the "standard conditions" used.  It belongs here. Gene Nygaard 00:07, 9 September 2005 (UTC)
thread_title:  Local Military Std 

message: Based on my 30 years of experience as a chemical engineer working in Europe and in the USA, I offer these comments:
* What this articles labels as being the "Old" standard is still being used far, far more often than what is labeled as being the "New" standard.  Very few practicing engineers are even aware of the "New" standard.  I would suggest deleting the words "New" and "Old" and simply state that both are used.
* There are literally a dozen or more definitions of standard temperature and pressure conditions in use in the metric world as well as in the USA.  Besides national preferences, many industries prefer their own standards.  This article should include a very prominently displayed caution that whenever publishing any gas flows (or quantities, or data of any kind) that are dependent upon  reference or standard conditions of temperature and pressure, then the author should clearly state the specific temperature and pressure conditions that apply. 
mbeychok 22:49, 21 January 2006 (UTC)
replies: text: Hi!  If you wish, you can go ahead and be bold in making changes like that, since they don't seem to be very controversial, and you probably know what you're mean best.  If anyone disagrees, one can always go to the talk page afterwards.  I can help out too, if you like.  Happy editing! --AySz88^-^ 03:52, 27 January 2006 (UTC)
thread_title: New versus Old

message: There appears to be a typo in the phrase
"gas volumes as being 0 °C (298 °K)" —Preceding unsigned comment added by 141.157.99.53 (talk • contribs) 11:29, February 4, 2006 (UTC
:Thanks for picking that up. It has been fixed.
:mbeychok 23:42, 4 February 2006 (UTC)
thread_title:  0<sup>o</sup>C vs. 25<sup>o</sup>C 

message: First let me thank you, Crissov for your editing help. I really appreciate you're taking the time to help. I have made changes to your revisions as follows:
# I disagree with using the term "English system of units" to replace "customary USA units".  Many readers will interpret English system to mean Imperial system and that will cause confusion.  As you know, there are many differences between the Imperial system and the customary USA units.  Two notable examples: the Imperial gallon is 20% larger than the US gallon, and the Imperial billion is 1012 whereas the USA billion is 109.
# The NIST is a national institute of the United States.  Altho knowledgeable scientists and engineers worldwide know that fact, there are many unknowledgeable readers  for whom I think that we should use U.S. National Institute of Standards and Technology when we spell it out.
# 15 °C is equal to 59°F rather than being approximately equal, so I changed it back to that.
# I don't see where putting parentheses around the °C, °F, kPa, psia, and % RH in the column headings of Table 1 added anything beneficial to the table.  In my opinion, that simply tends to clutter the table, so I removed the parenthesis.
# Altho chemists and physicists are acclimated to using the term "mol" for a gram mole, there are thousands of engineers (chemical engineers in particular), scientists and environmental regulators who are acclimated to explicitly differentiating between gram moles, kilogram moles (i.e., kgmol), and pound mols (i.e., lbmol) who might be misled  by the use of "mol" instead of gram mole or gmol. I think is is very important to use the more explicit term "gmol" instead of "mol" so as to avoid mistakes. As a matter of interest, I am amazed that there is not yet any mention that I could find of the term "lbmol" or "pound mol" anywhere in the Wiki as yet.
# I don't agree with your exclusion of the list of the acronyms used in Table 1 which included their spelled-out names.  I am sure that many of those acronyms will not be known to all readers of the article.  Some of them may not even know what ISO or IUPAC means much less all of the others.  So I have reinstated that list.
# Don't you think that your method of listing the acronym on one line and the spelled out name on another line just makes the list longer for no really good reason?  I think the original listing of the acronym followed by the spelled out name on the same line was a good deal more compact.
# I made a number of other very inconsequential changes that I really can't remember well enough to list.
I fully realize that some of my comments above may not be in line with Wiki style but I am sure that there is room for some discretion. I also believe that it is important to keep in mind (as I said above) that there are many engineers, scientists and others who have adopted certain usages that may not yet be recognized in the Wiki styles. In the short time that I have been involved in Wiki, I have gotten the distinct feeling that evolution and development of the Wiki did not involve many experienced chemical engineers. 
Wow! It is now 1:30 AM in California and that is late for an 80-year old retired engineer!! Good night to all.< mbeychok 09:38, 14 February 2006 (UTC)
replies: text: Thanks for fixing my mistake. - mbeychok 17:21, 29 March 2006 (UTC)
thread_title: Comments on revisions made by Crissov

message: Cleanup is in progress with the editing help of User:Crissov. I can not find a tag that says that, so I am removing the cleanup tag.  I hope that is okay. mbeychok 18:13, 14 February 2006 (UTC)
thread_title: Cleanup is in progress

message: Hi!  I think that the name of each standard condition should be added if possible, so that the reader can see whether a certain temperature-pressure-humidity combination is called "Standard Temperature and Pressure" (STP) or "Normal Temperature and Pressure" (NTP) or something else. Thanks...
:The basic point of the whole article is to show that there simply is no universally accepted STP or NTP or any other such name.  As shown in the table, various organizations and entities have all established their own different definitions for those names.  As stated in the article, "The table makes it quite obvious that it is absolutely necessary to clearly state the temperature and pressure reference conditions whenever expressing a gas volume or gas volumetric flowrate." - mbeychok 17:15, 29 
March 2006 (UTC)
::I see your point, but I think the information about standard names would still be helpful in some cases: For example, the conditions used when I was at school here in Finland were officially called NTP conditions and I'd like to find out what exactly those conditions were. So, if the list of different standard conditions in the article had names (STP, NTP etc), I would have a more limited subset to choose from when trying to find out what the NTP in that case referred to. (Well, my best guess is 101,325 kPa and 20 degrees Celsius.)
::: I don't know what more to tell you.  It is not up to you or I to decide which standard conditions shall be labeled STP or NTP.  It is up to the entire community of engineers, chemists, scientists, professional organizations, etc. to form a concensus and define those conditions.  As shown in the article as it now stands, it is quite obvious that there is no such consensus.  The only prudent thing you or I can do is to always clearly state what T and P we used as reference conditions whenever we write a report, publish a technical article or book, or send each other emails. It is very easy to to be mis-understood if we are not careful.  For example, just above you refer to 101,325 kPa whereas I, as an American, use 101.325 kPa for atmospheric pressure ... so you see we must even be careful to explain what delimiter we use as a decimal point indicator. To me, 101,325 means one hundred and one thousand, and three hundred and twenty-five. To you, it means one hundred and one, and three hundred and twenty-five thousandths. Regards, - mbeychok 09:24, 10 April 2006 (UTC)
thread_title:  Names of the standard conditions would be helpful 

message: Sadi, I have partially reverted and revised your recent edits of this article. In my opinion, your comments were too focused on the the definition and usage of STP from the viewpoint of chemists and thermodynamicists. Standard reference conditions are used throughout industry and other fields for many reasons other than for defining "experimental measurements". For example, standard reference conditions are used: to define gas and liquid flow measurements in gas delivery contracts by pipeline companies among others; to define test conditions during the performance testing of equipment such as compressors and gas turbines; and very widely used by engineers to define industrial process material balances. I don't agree that such usage should be characterized as "Technicalities". I know that you didn't intend to be disdainful of usages other than those of the chemists and thermodynamicists, but that is how your editing was perceived by me. I also don't think that your sentence about being "earth bound" is at all necessary nor does it add any substantive knowledge to the article.
Yes, STP has for many years in the past been defined as 273.15 K and 1 atmosphere, but that is no longer true. The IUPAC definition is currently 273.15 K (0 °C) and 1 bar. And one of the International Standard Organization's (ISO) current definitions is 15 °C and 1 atmosphere. The IUPAC and the ISO are both internationally accepted.
I don't see how the various reference conditions documented in Table 1 can be interpreted in any other way other than as done in the lead-in paragraphs, namely: The available data on the various definitions of standard reference conditions clearly indicates that currently there is no universally accepted definition of the standard conditions of temperature and pressure.
Besides partially reverting and revising your edits, I also re-wrote some of my previous edits so as to be more encyclopedic and less informal. I thank you for bringing that to my attention. Regards, - mbeychok 21:56, 1 May 2006 (UTC)
thread_title: Partial reversion of edits by [[User:Sadi Carnot]]

message: This is a good source of information, but as I have noticed, and personally experienced. The current way the document is organized leads to quite a bit of confusion. We need to find a way to better organize. I would love to spend a day rearranging the text, but I lack in depth understanding of the more complex Wikipedia markup that would be necessary. What can be done about this? Does any one person have a good Wikipedia markup tutorial. And how does one go about adding a document to  the "Article of the Week" project?  - Turbinator 16:39, 1 November 2006 (UTC)
replies: text: It is a good idea, before making any extensive major revisions, to first discuss here on this talk page exactly what you propose to do ... and see if a consensus can be reacehd. That may also encourage others to to help you do the markup or even to do it for you. Regards,  - mbeychok 01:26, 1 November 2006 (UTC)
thread_title:  Document Organization 

message: Laurascudder: I am not a physicist so I will not dispute your importance rating of B. However, from what I read in the Wikipedia:Version 1.0 Editorial Team/Assessment article, it does indeed deserve the Class A rating so I reverted the class rating to A. Regards, - mbeychok 04:33, 11 December 2006 (UTC)
thread_title:  Reverted Class rating to A 

message: User:JW, I moved your sentence about the US Standard Atmosphere's value of the gas constant R to the bottom of that section ... rather than leaving it in the middle of the two equations where it interrupted the flow of the section.  Also please read Gas constant and especially Gas constant#USAA Standard Atmosphere. - mbeychok 20:27, 23 January 2007 (UTC)
thread_title:  Value of R 

message: Please... add CODATA
http://physics.nist.gov/cgi-bin/cuu/Results?search_for=volume+molar values to volume molar. Thanks from Brazil. - 
user Mago® from wiki-pt 
: I added your above link to the CODATA values on the NIST wbesite as a reference in the "Molar volume of a gas" section of this article. - mbeychok 20:00, 1 May 2007 (UTC)
replies: text: Yes! Very good! user Mago® from wiki-pt  —The preceding unsigned comment was added by 200.161.59.67 (talk) 04:38, 2 May 2007 (UTC)
thread_title:  CODATA 

message: it is a little annoying that i have to read the page for a minute to get crucial, basic, and the most commonly used information.
this is what i was looking for: http://chemistry.about.com/library/glossary/bldef855.htm.
please make the info 90% of people want to see more clear and focused intead of obscured in midst of a winding paragraph. —Preceding unsigned comment added by 64.142.4.31 (talk • contribs) 4 February 2008 (UTC)
:Gosh, I am sorry you had to spend a minute to read this article ... a whole 60 seconds!! Wow!! Yes, the one-liner in About.com is indeed simple ... it is also simply wrong! You really should tell Anne Marie Helmenstine, Ph.D. (who wrote that one-liner) to read this article and please tell her to take more than one minute doing so. 
:By the way, comments on Talk pages don't get inserted in the middle of the page. They get inserted at the bottom of the page. And they should be signed. All you have to do is write ~~~~ and your name will get signed and dated automatically. Isn't that a great way to save time?? It is also useful if one uses capitalization where it is meant to be used ... it makes a better impression on those who read the comments. 
: All that aside, the main message of this articles is that the available data on the various definitions of standard reference conditions clearly indicates that currently there is no universally accepted definition of the standard conditions of temperature and pressure. And also it is absolutely necessary to clearly state the temperature and pressure reference conditions no matter what standard or other name you give those conditions. - mbeychok (talk) 06:42, 5 February 2008 (UTC)
thread_title:  too complicated 

message: Anyone got a new link? Headbomb {ταλκ – WP Physics: PotW} 04:09, 25 July 2008 (UTC)
thread_title:  The link for SPE ref is broken 

message: I changed "For a great many years.." to "For the past 5-6 decades..." and then removed the "Clarify me" template. I might add that the old values probably date back even further and some people (who are unaware of IUPAC's current value or simply disagree with it) still use the old values. GradEngr (talk) 21:08, 27 July 2008 (UTC)
thread_title:  "Clarify me" template now satisfied and removed 

message: I had been looking for the meaning of the abbreviation ANR, which I see in the specs of pneumatic devices. I eventually found out it is an abbreviation for "conditions de l’atmosphère normale de rèfèrence' which is French for "standard reference atmospheric conditions" (see this document).  That's about all I know, but if you can find a way to incorporate this into the article, I think it would be helpful to some people.  When I was searching for the meaning of this abbreviation, Google didn't give up the answer without a fight! ike9898 (talk) 20:58, 25 September 2009 (UTC)
thread_title:  ANR 

message: What is the difference between STP and NTP ? why?  —Preceding unsigned comment added by Shivaaprs (talk • contribs) 05:25, 5 April 2010 (UTC)
replies: text: This is a glaring omission. Half of the world uses NTP. 85.76.7.236 (talk) 19:10, 18 July 2010 (UTC)

text: Resolved TomyDuby (talk) 12:20, 26 November 2015 (UTC)
thread_title:  STP vs NTP 

message: --George Kluney (talk) 20:25, 7 April 2010 (UTC)
thread_title:  EPA's STP 

message: Should we use litres and kPa in the ideal gas equation, or m3 and Pa? I prefer the latter. R = 8.31 J mol-1 K-1 and it's much easier to see that J is related to m3 Pa than it is to L kPa. kPa and L are not base units either.
Ewen (talk) 21:17, 31 May 2010 (UTC)
thread_title:  Molar volume of a gas 

message: Being a chem student, I was more than a little frustrated not to be able to find any information here that didn't require reading through lines and lines of useless junk speculation. I created an account just to put on a name to the adjustment to the article that I made that would make the information actually accessible to people like me; of whom, I assure you, there are many.  —Preceding unsigned comment added by Emudd (talk • contribs) 21:23, 15 September 2010 (UTC)
thread_title:  Frustration 

message: I have found (yet) another standard, ISO 6358 which defines standard reference conditions for air as 20°C and 100 kPa and 65% RH.  It appears to be used in Germany.  I don't have a copy of the standard but it is referenced in Pneumatic Drives: System Design, Modelling and Control By Peter Beater, page 42 . Perhaps someone who has access to ISO standards can check this and add to the ever growing list. Turner chris1 (talk) 12:07, 11 October 2012 (UTC)
thread_title:  Yet another ISO standard  

message: I just added the 22C standard which is used in medical physics.  Possibly too small a subdiscipline to be included here, but I don't see the harm.  No idea why medical physics needs it's very own non-standard standard, but it fits with everything else I've learn about the field. jwandersTalk 22:55, 31 July 2014 (UTC)
thread_title:  TPS Standard for american medical physics 

message: I'm not sure if this belongs here or in an article on Thermodynamics or possibly Thermodynamic Equilibrium, but there are problems with "standard conditions" because they assume other variables are fixed (or vary insignificantly). A couple of examples: Pressure, as used here, applies well to Ideal Gases and less well to real gases. It doesn't apply to liquids or solids, although it is commonly used for them. A thermodynamic system at 101 kPa and 25°C and 1 gravity bears little resemblance to the 'same' system at 101 kPa, 25° and 1 million gravities (ok, an extreme example, I admit). Similarly, a system at constant T & P but with a neutron flux of 10^6 times higher wouldn't necessarily have much similarity to one at "STP". Also, often a "standard atmosphere" assumes a composition ([N2], [O2], [H2O], etc.) Although this article has numerous cautions about the variation in meanings, I didn't see cautions about these dimensions of the meaning of "Standard".72.172.1.40 (talk) 19:23, 23 September 2014 (UTC)
thread_title:  Missing criticism section 

message: Hello fellow Wikipedians,
I have just added archive links to  on Standard conditions for temperature and pressure. Please take a moment to review my edit. If necessary, add  after the link to keep me from modifying it. Alternatively, you can add  to keep me off the page altogether. I made the following changes:
*Added archive https://web.archive.org/20071018212002/http://www.gassco.no/sw3138.asp to http://www.gassco.no/sw3138.asp
*Added archive https://web.archive.org/20101006154629/http://www.nist.gov:80/pml/data/star/index.cfm to http://www.nist.gov/pml/data/star/index.cfm
When you have finished reviewing my changes, please set the checked parameter below to true to let others know.
Cheers. —cyberbot IITalk to my owner:Online 15:23, 27 August 2015 (UTC)
thread_title:  External links modified 

message: Common use of this term is STP in documentation, which means Standard Temperature and Pressure. Standard Conditions for Temperature and Pressure would be SCTP, which I do not believe is standard usage, please verify. The conditions portion of the title is more descriptive but should only be included in the definition. This page is probably viewed more than most of us would assume, so lets clean this mess up. The data is great. The presentation is confusing and sloppy. I see there was actually a student complaint on this issue. Considering the wide application and usage of STP, its variations per field of study, even among high ranking programs in particular fields, simplification and modification of this article is a priority. I will attempt to archive this article, and reverse the redirection. I will preserve individual credit for input whenever possible. Omegamultiverse (talk) 23:23, 8 January 2016 (UTC)
thread_title: I believe this page is redirected in error

message: Substituted at 06:53, 30 April 2016 (UTC)
thread_title: Assessment comment

message: The newest (2018) edition of Handbook 44 defines NTP as the following:
"NTP. – Normal Temperature and Pressure of a cryogen at a temperature of 21 °C (70 °F) and a pressure of 101.325 kPa (14.696 lb/in2 absolute). [3.34]"
So if I'm correct, the article should be changed according to this new definition, from 20 °C to 21 °C.
Or am I missing something here?  — Preceding unsigned comment added by Assaiki (talk • contribs) 09:03, 25 August 2018 (UTC)
thread_title:  NTP changed? 

message: The petroleum industry usage of 60 °F is equal to 15.56 °C. The table shows 16 °C. Please correct the table to show the Celsius temperature to at least two decimal places.DLH (talk) 21:25, 8 May 2019 (UTC)
thread_title:  Show 60 °F as 15.56 °C not 16 °C 

message: I think this page should be renamed to "Standard Temperature and Pressure".  That's what the common acronym STP stands for, and it seems to be the much more common phrase, e.g. in google hits.  Is there a reason for the current name that I'm missing? Danstronger (talk) 00:01, 19 October 2021 (UTC)
thread_title:  Name change to "Standard Temperature and Pressure"? 

message: Relationship between standard pressure and standard temperature 119.160.68.36 (talk) 06:35, 10 June 2022 (UTC)
thread_title:  Mathematical relationship between standard temperature and standard pressure