Talk:Standard conditions for temperature and pressure

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0oC vs. 25oC[edit]

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)

101325 Pa vs. 105 Pa[edit]

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)

Local Military Std[edit]

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))

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)

i searced a little: The ARMY STANDARD METRO atmosphere was established at the U.S. Army Aberdeen Proving Ground and was used for many years by the U.S. Army as the atmosphere for which all standard firing tables were computed. This standard atmosphere was also adopted by the manufacturers of commercial ammunition, and it is still in use by the major manufacturers of commercial ammunition and bullets. In the Army Standard Metro, the atmosphere at sea-level has a temperature of 59 degrees F., a barometric pressure of about 29.53 inches of mercury, and a relative humidity of 78 percent. The atmospheric density under these conditions is about .0751 pounds per cubic foot.

it still looks like a National Std. if it is international used than I agree with Gene, but I have not been able to proove that perhaps Gene or someoene else could check?

its also loking as it is based on 750mmHg and the inch values are calculated found that at http://www.absoluteastronomy.com/encyclopedia/s/st/standard_conditions_for_temperature_and_pressure.htm :

The Army Standard Metro atmosphere, now used only in (The science of flight dynamics) ballistics, defines sea-level conditions as 750.000 mmHg of pressure (29.5275 inHg, 99.9918 kPa), 59F (15degC), and 78% (Wetness in the atmosphere) humidity. (Ref: U.S. Army Ballistic Research Laboratory, U.S. Army Aberdeen Proving Ground)

as seen above area of use is not compleetly clear as well, can wee keep it here at the discussion, till we worked all out?

If we consider National Standards to be published here or elsewere, also this national Std should be considered:

U.S. Standard Atmosphere 1976 United States Committee on Extension to the Standard Atmosphere (COESA) Parameter: Atmospheric density, temperature, and pressure

Brief Description: The work of the U.S. Committee on Extension to the Standard Atmosphere (COESA), established in 1953, led to the 1958, 1962, 1966, and 1976 versions of the U.S. Standard Atmosphere. These models were published in book form jointly by the National Oceanic and Atmospheric Administration (NOAA), the National Aeronautics and Space Administration (NASA), and the U.S. Air Force. Altogether 30 U.S. organizations representing government, industry, research institutions, and universities participated in the COESA effort. Based on rocket and satellite data and perfect gas theory, the atmospheric densities and temperatures are represented from sea level to 1000 km. Below 32 km the U.S. Standard Atmosphere is identical with the Standard Atmosphere of the International Civil Aviation Organization (ICAO). The U.S. Standard Atmospheres 1958, 1962, and 1976 consist of single profiles representing the idealized, steady-state atmosphere for moderate solar activity. Parameters listed include temperature, pressure, density, acceleration caused by gravity, pressure scale height, number density, mean particle speed, mean collision frequency, mean free path, mean molecular weight, sound speed, dynamic viscosity, kinematic viscosity, thermal conductivity, and geopotential altitude. The altitude resolution varies from 0.05 km at low altitudes to 5 km at high altitudes. All tables are given in English (foot) as well as metric (meter) units. The U.S. Standard Atmosphere Supplements, 1966 includes tables of temperature, pressure, density, sound speed, viscosity, and thermal conductivity for five northern latitudes (15, 30, 45, 60, 75), for summer and winter conditions.

Availability: In hard copy from the National Technical Information Office, Springfield, Virginia (Product Number: ADA-035-6000). The Fortran code can be obtained from Public Domain Aeronautical Software. A DOS executable and turbo pascal source code is available from Small World Communications.

References: U.S. Extension to the ICAO Standard Atmosphere, U.S. Government Printing Office, Washington, D.C., 1958.

U.S. Standard Atmosphere, 1962, U.S. Government Printing Office, Washington, D.C., 1962.

U.S. Standard Atmosphere Supplements, 1966, U.S. Government Printing Office, Washington, D.C., 1966.

U.S. Standard Atmosphere, 1976, U.S. Government Printing Office, Washington, D.C., 1976.

there is work ahead, opinions please

Wilhelm.peter 16:11, 9 September 2005 (UTC)

New versus Old[edit]

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)

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)

Complete Revision[edit]

I have just completely revised this article so that it accurately reflects current usage. I also added a good many categories (other than simply chemistry and measurement) because the subject matter applies to many physical science and engineering fields. Further, I removed the external link to Normal temperature and pressure because it also needs to be updated, which I will do by redirecting from that article to this one. Finally, I deleted discussions of other subject matter which were really not directly apropros to the subject matter of this article.

The categories listed at the bottom of the edit page for this article includes many categories in languages other than English. I don't know what to do about them ... so I left them there unchanged.
mbeychok 19:44, 3 February 2006 (UTC)

Thank you for working on this article! I'll try to help to wikify it (put it into the same kind of format as other Wikipedia entries) soon; meanwhile, feel free to continue editing if you wish.
By the way, the list on the bottom aren't categories, they are for the "this article in other languages" section at the bottom of the left sidebar. --AySz88^-^ 03:43, 4 February 2006 (UTC)

0oC vs. 25oC[edit]

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 (talkcontribs) 11:29, February 4, 2006 (UTC

Thanks for picking that up. It has been fixed.
mbeychok 23:42, 4 February 2006 (UTC)

Comments on revisions made by Crissov[edit]

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:

  1. 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.
  2. 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.
  3. 15 °C is equal to 59°F rather than being approximately equal, so I changed it back to that.
  4. 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.
  5. 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.
  6. 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.
  7. 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.
  8. 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)

[I changed the imperial and US billion from 109 and 106 to 1012 and 109, right into the text. This is one point where the Wiki system may be a bit too liberal: I can make changes not only to articles but to other peoples' comments so that the impression is as if my words were written by the original author. -- An visitor remaining anonymous]

Thanks for fixing my mistake. - mbeychok 17:21, 29 March 2006 (UTC)

Cleanup is in progress[edit]

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)

Standard conditions symbol[edit]

I do not hope I am too off-topic here. In some situations a special symbol is used to mean "standard". The symbol in question looks like an 0 with a horizontal line through it. Not identical (but somewhat similar) to the Greef letter Θ. It can be seen here, in a symbol for standard molar entropy. In a Danish-language high-school textbook I have, the symbol is called "the standard sign" (standardtegnet).

Does anyone know information about this symbol? Is it included in Unicode (where)? /217.116.235.34 10:30, 20 February 2006 (UTC)

User:217.116.235.34:
The US National Institute of Standards and Technology (NIST) uses something fairly similar to your Danish symbol to denote the standard state of thermodynamic properties. For instance, NIST denotes the standard entropy of a chemical as So and the standard enthalpy of formation of a chemical as fHo. The "Handbook of Chemistry and Physics" published by CRC Press, denotes the standard entropy of a chemical as So and the standard enthalpy of formation of a chemical as ΔHfo. That usage of a o to denote the standard state seems to be used mostly in the fields of chemistry and chemical thermodynamics. - mbeychok 23:21, 27 February 2006 (UTC)

Names of the standard conditions would be helpful[edit]

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)

Regarding the Wikify tag by Stevertigo[edit]

I am at loss to see why you feel this article needs more Wikifying.

  • It has a lead-in paragraph which includes the article title in bold print in the opening sentence.
  • It has a navigation box following the lead-in.
  • It has a great many words in the text that have wikifying links to other Wikipedia articles.
  • The table is a wikiclass table.
  • There are a host of internal wikifying links, one for each of the specific organizations listed in the main table of data ... and it is important that those be closely associated with and "tied" to the table.
  • There is an external links section at the end of the article for generalized information available from external sources
  • There is a reference list with a great many references using the Wiki methodology of {{ref label}} and {{note label}}
  • A number of relevant categories have been specified for including the article.

It seem to me that all of the above is completely in line with the Wikipedia:Guide to layout.

If you will tell us what you think needs more wikifying, I for one shall do my best to do so. However, until then, I think the article is wikified as it now stands and I am therefore removing the your tag.

Partial reversion of edits by User:Sadi Carnot[edit]

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)

99.992 kPa ≈ 1 bar is correct as is. Please don't change again.[edit]

Please read these opening paragraphs from Wikipedia:Manual of Style:

This Manual of Style has the simple purpose of making the encyclopedia easy to read by following a consistent format — it is a style guide. The following rules do not claim to be the last word on Wikipedia style. One way is often as good as any other, but if everyone does it the same way, Wikipedia will be easier to read and use, not to mention easier to write and edit. In this regard, the following quotation from The Chicago Manual of Style deserves notice:

Rules and regulations such as these, in the nature of the case, cannot be endowed with the fixity of rock-ribbed law. They are meant for the average case, and must be applied with a certain degree of elasticity.

In this vein, editors of new and existing articles should strive to have their articles follow these guidelines.

Clear, informative, and unbiased writing is always more important than presentation and formatting. Wikipedia does not require writers to follow all or any of these rules, but their efforts will be more appreciated when they do so: the joy of wiki editing is that Wikipedia does not require perfection.

[The bolding in the above has been added by User:Mbeychok for emphasis.]

Also please read the the Table of mathematical symbols. - mbeychok 14:58, 15 May 2006 (UTC)

They're all ≈ 1 bar. There's nothing particularly distinguishing this one from any of the others which are not exactly one bar. There's no good reason to round this off to while not rounding off ≈ 100 kPa or ≈ 15 psi. There's no particular reason to include the non-cgs and non-SI bars in any case.
Don't know how your rambling about style guides has anything to do with the rough approximation to 1 bar. Gene Nygaard 04:32, 17 May 2006 (UTC)
So now 99.992 kPa ≈ 1 bar is a rough approximation? Just what would it take for you to call it a good approximation rather than a rough approximation? Most people who are not obsessive about styles would be satisfied to accept 99.992 kPa as being equal to 1 bar for all practical purposes ... the very thought of that probably makes you shudder. The reason that I asked you not to change it again is because you had removed the ≈ 1 bar completely in one of your previous edits. That is also the reasoning for my providing the above direct quote from the Wikipedia Manual of style ... which you have dismissed out of hand as "ramblings". I am sure that the people who wrote that Manual would love to know that you think it is "rambling". Gene, I want to acknowledge as I have done before that most of the edits you have made in this article and others were correct ... but you sure do tend to go overboard sometimes. Its a bad habit. - mbeychok 05:22, 17 May 2006 (UTC)
Yes, it is a rough approximation, and there is no good reason not to express all the conversions to the same precision. Why not, for example, "0.99992 bar" and "100 kPa"? Why not "101.325 kPa ≈ 1 bar"? Gene Nygaard 12:54, 17 May 2006 (UTC)
Or, if you are going to go by that "for all practical purposes" reasoning, why are you considering 750 mmHg as distinct from 100 kPa? Gene Nygaard 13:01, 17 May 2006 (UTC)

kPa or Pa-ideal gas law[edit]

when using the ideal gas law to have an outcome in kgmol (or kmol) kPa should be used? no? - 2nd year chem eng Student (adeliade, Australia) Someone with more expertise may be able to rectify with more confidence than me??

Not necessarily so. It depends on the units used for the gas constant R. What is necessary is to always do some dimensional analyis and see that that all of the units used in your gas law calculation are consistent. See Units conversion by factor-label article. - mbeychok 16:09, 20 June 2006 (UTC)

With this in mind it appears to me that there is a typo in the section "Molar Volumes of Gas". In the lines of text such as

  V ÷ n = 8.3145 × 273.15 ÷ 101.325 = 22.414 m³/kmol at 0 °C and 101.325 kPa absolute pressure 

the units of the left hand side do not match the right hand side, given than n is earlier defined as number of kgmol.192.102.214.6 17:47, 4 October 2006 (UTC)

The units on both sides of (V / n) = (R T /P) are:
m³ / kgmol = (m³ • kPa) / (kgmol • K) (K / kPa)
If we cancel out similar units in the numerators and denominators of the right hand side, we get the same units as the left hand side, namely m³ / kgmol. Is that not correct? - mbeychok 21:46, 4 October 2006 (UTC)

STP vs SATP[edit]

I'm confused by the article... I was searching for the values for SATP, which as learned from high school, I remember as 25oC... however, SATP redirects to STP, and I was misled... only temporarily, however... could a better distinction be made, or is the term "SATP" not in use anymore? Kareeser|Talk! 23:38, 31 July 2006 (UTC)

Kareeser, the best advice I can give you is to read the article again, slowly and carefully. In particular, study Table 1. One of the primary purposes of the article is to show that there are many, many different sets of standard conditions in use today by various organization, agencies and other entities. In fact there are so many, that using terms such as STP or SATP is quite meaningless unless you specify exactly what temperature and pressure you are using as the reference or standard conditions.
To specifically answer your comment, to the best of my knowledge, SATP is in some use today but it it is not very common .. and if you use it, you should carefully state what reference temperature and pressure you are using. It is a mistake to assume that people will understand what your reference conditions are unless you spell them out. I hope this helps clear up your confusion. - mbeychok 00:18, 1 August 2006 (UTC)

Document Organization[edit]

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)

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)

Reverted Class rating to A[edit]

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)

100 kPa and 101.325 kPa[edit]

I'm a civil & environmental engineering student, and before my most recent revision, the opening of this article made it seem like standard pressure is now universally used as 100 kPa. This is not true: probably mostly influenced by the EPA, environmental engineering students use 101.325 kPa as standard pressure, at least here in Iowa. My revision makes it clear that there is not 1 universally used definition, but even my revision is not perfect and if it could be improved, that would be nice.

-One corollary to this is that if you want 1 mol of gas to occupy 22.414 litres of space at STP, you MUST use 101.325 kPa - if you use 100 kPa, then you get 22.711 litres (unless of course you modify R from 8.3143 cubic-meter pascals per mole-kelvin).JW 07:09, 23 January 2007 (UTC)

With all due respect, you seem to have missed the entire point of the article ... which is that there is no universally accepted set of standard conditions. The second paragraph in the lead-in paragraph states: The available data on the various definitions of standard reference conditions clearly indicates that the IUPAC's STP is not a universally accepted definition of the standard conditions of temperature and pressure. How much clearer can that be? All one has to do is read more than just the first paragraph.
The tabulation included in that table makes the same point quite clear.
I see no point in adding that sentence about American environmental engineers and am deleting it. - mbeychok 18:47, 23 January 2007 (UTC)

Value of R[edit]

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)

CODATA[edit]

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 [1]

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)
Yes! Very good! user Mago® from wiki-pt [2] —The preceding unsigned comment was added by 200.161.59.67 (talk) 04:38, 2 May 2007 (UTC).

too complicated[edit]

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 (talkcontribs) 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)

Layout of Table 1[edit]

You have now changed Table 1 twice from its original form which has been there for over two years (since March 11, 2006) without any changes or complaints. This is exactly why you were very recently denied your request to become an administrator! Your belief that you know better than anyone else and your refusal to accept anyone else's opinion.

You argued with everyone who opposed your request to be an administrator just as you are now arguing with my polite request that you cease changing the layout of Table 1.

Once more, would you please change Table 1 back to its original layout? If not, I must conclude that you are doing this only out of spite because I was one of those who opposed your request for adminship. mbeychok (talk) 05:41, 23 July 2008 (UTC)

Please stop accusing me of know-it-allness and to make shoddy parallels with irrelevant things. The former table had dozens of notes to give conversions for everything there. I placed it in a more convenient format with no need to punch things in a calculator. Things are not automatically better because they are old. I also suggest you reading WP:OWN. Headbomb {ταλκWP Physics: PotW} 06:08, 23 July 2008 (UTC)
I fully agree with you that "Things are not automatically better because they are old." ... but that isn't the point. The point is that hundreds of people have read this article in the two and half years since March, 2006. None of those readers voiced any opinion that the Table needed to be changed or that they had a problem with the conversion notes at the bottom of the table ... until you came along with your propensity of believing that you "know better" than anyone else that the Table needed changing.
The intent was for the table to make a strong, visual impact on readers with the fact that many organizations had various standard conditions so that the point was made that there is no universal set of standard conditions. That visual impact is now lost because the table now just looks like a table of conversions. That is very definitely the impression that it makes. mbeychok (talk) 07:43, 23 July 2008 (UTC)
Encyclopedias are compendiums of information. There's more information in the table now, all of it useful and well formatted. It's certainly a lot better than having a table with half the information contained in footnotes (if your willing to do conversion yourself). There's just as many standards listed than before so I really don't see how a reader would interpret this as an indication that there is a universal standard out there. The table could be improved however, since it is not clear in which unit these organization define their standards. If you still have a problem with my edits, I suggest contacting Wikiproject physics and Wikiproject Chemistry for comments. Headbomb {ταλκWP Physics: PotW} 08:12, 23 July 2008 (UTC)
IMO, the difference between the tables is not a big deal. However, I think Headbomb's version has too many columns. I would only include the units that were actually used for defining these standards, which would leave only deg C, deg F, atm, bar or kPa, and inHg. Also note that you made a big mistake in the last row, by confusing inches of mercury with millimeters of mercury. I also suggest bolding or otherwise highlighting the cells that actually define a standard. --Itub (talk) 14:01, 23 July 2008 (UTC)
I'll check the mmHg/inHg thing. I ain't too sure about axing columns down (other perhaps than the degrees Rankine one), as all these units are currently used in various industries.Headbomb {ταλκWP Physics: PotW} 14:57, 23 July 2008 (UTC)
I fixed the AMCA entry. Headbomb {ταλκWP Physics: PotW} 14:57, 23 July 2008 (UTC)

For what it's worth, IMHO, the original table better achieved the purpose of illustrating the different standards. Having all the values converted isn't helpful in this case. Information hiding and progressive disclosure are User-centered design principles that apply to good writing as well. Samw (talk) 21:51, 23 July 2008 (UTC)

I am going to seconds this. The new table is way too big, and has many superfluous fields. Having one temperature and one pressure in the list is enough, if the units have a link, recalculation can be done easily. The new table is way too big, and as said, this does not illustrate the different standards, it is a recalculation table. May I suggest reversion to the old table, and discussing things first (especially since there was already early in the process some comments on the new table)? --Beetstra (public) (Dirk BeetstraT C on public computers) 14:38, 24 July 2008 (UTC)
I'll slash the rankine, bars and mmHg. That should help. Headbomb {ταλκWP Physics: PotW} 15:14, 24 July 2008 (UTC)
It helps, but still, only one temperature scale and one pressure scale demonstrates the differences better. And also, I think the column for publishing or establishing entity should move to the right column, not be the first column. A third change would be that the publishing or establishing entity could easily be a wikilink, which removes the necessity of the notes section almost completely, and finally, make a seperate column for the references, which would improve the readability of the publishing or establishing entity column even more. --Beetstra (public) (Dirk BeetstraT C on public computers) 15:24, 24 July 2008 (UTC)
I don't think we can slash the columns further without harming the value of the table. Kelvin and Celsius needs to be there since these are respectively the scientific units, and the common metric units. Fahrenheit needs to be there mostly because of American (and maybe British) readers and many of those standards are given in Farenheits. Same goes for pressure, kPa = scientific, psi = american and british readers, atm = gives a sense of scale to laypeople.
Publishing entities need to be kept on left, as you need a to first identify the standards. Notes and references however, could use a cleanup. Headbomb {ταλκWP Physics: PotW} 15:50, 24 July 2008 (UTC)
The value of the table is comparing, not giving a complete overview. Therefor, only one temperature scale, and one pressure scale is more than enough. Now it is more difficult to see what changes with all the values. And as generally, first you make the statement, then you give the reference, and as we are comparing the different temperatures and pressures, those are the columns which are more important, and hence it makes more sense that they are on the left. I am sorry, Headbomb, there are several people here who suggest this here, I still think that the original table was more clear, except that I would suggest to make links to the entities inside the table, not as notes below. --Beetstra (public) (Dirk BeetstraT C on public computers) 16:01, 24 July 2008 (UTC)
I agree with Beetstra. Columns for temp, pressure, humidity and entity, in that order, with wikilinks instead of notes. --Kkmurray (talk) 17:46, 24 July 2008 (UTC)
But that makes no sense. You need to identify things before you list them. See Electrical resistivity#Table of resistivities for an example of a well formatted table. It wouldn't make much sense to list the properties first, then identify the material.Headbomb {ταλκWP Physics: PotW} 17:56, 24 July 2008 (UTC)

There's only one person so far who commented on the latest version of the table (you). It's rather pre-emptive to suppose that this version is deemed inferior by consensus. I'll ask for comments on WP Physics and WP Chemistry. Headbomb {ταλκWP Physics: PotW} 16:35, 24 July 2008 (UTC)

I have been keeping an eye on this discussion, but have not commented previously. I see you have asked for comment on Wikipedia talk:WikiProject Chemistry, so I will comment. I too liked the original version and I generally agree with the comments by Beetstra above. I think the visual impact was good and now that is largely lost. I too think the entity column should be at the right. Headbomb's argument that this makes no sense is just wrong, as it is OK to reference a fact after stating it. I see no reason to have a column for Farenheit. Keep it simple. --Bduke (talk) 23:59, 24 July 2008 (UTC)

And, Headbomb, I am not the only user who likes the previous version better, as you can see above (before User:Bduke commented), User:Mbeychok, and user:Samw both also had a preference for the original table, and User:Itub and user:Kkmurray also say it had too many columns (of which you stripped a couple aready).
Re Headbombs '.. It wouldn't make much sense to list the properties first, then identify the material.' That is completely different. There you are talking about the material, then about their properties, which is completely right (the table is about the resistivity of different materials, so you name the materials first, right?). Here we are talking about the different standards pressures and temperatures, but they do not get named first.
There is nothing wrong with being bold in changing something that has been there for years without previous discussion, but if there is following discussion on the subject, and some editors do question the new format (all with about the same reasons), then it is time to revert, and discuss and achieve consensus here (or on a wikiproject), before reapplying the changes. --Dirk Beetstra T C 09:12, 25 July 2008 (UTC)
I really don't see any difference between naming materials, then listing their properties, and naming standards, then listing their "properties". All lists of standards on wikipedia are formatted in this way (see List of ISO standards, List of IEC standards, List of EN standards, European emission standards, and many others). Nor am I quite sure of what you're accusing me of by mentioning something about "re-applying" changes. Headbomb {ταλκWP Physics: PotW} 14:13, 25 July 2008 (UTC)
There clearly are quite some who do see the difference (including me) between naming materials, and then their properties, and naming standards and then their 'properties' (the difference is, what is the table about). Even, while your argument is a non-argument, all 4 examples that you gave here, are lists of standards, they do not compare the standards, they simply list. If the title of the article would have been 'list of standard conditions for temperature and pressure', then your table would be an appropriate format (and the article would not contain much more than only that info). But it is not.
And you reverted Mbeychok's revert of your edits (diff), which is what I mean by 're-applying changes', while there is a clear opposition (at that time by only one person. I am going to revert to the old version of the table, which consensus here seems to prefer (and where there are quite a number of reasons for the old format). I am inviting you to discuss your order of columns here, and when you get consensus that that is to be the order, then that can be applied. But seen the 4-5 people who here state that the table in the old format was more clear, I don't think that will be the case. Thanks. --Dirk Beetstra T C 15:20, 25 July 2008 (UTC)
I would even go one step further: some of these standards are defined in degrees Fahrenheit, not in Kelvin or in degrees Centigrade. Although these are converted in a mathematical way, depicting them in Fahrenheit when they are defined in degrees Centigrade removes a part of information from the table. --Dirk Beetstra T C 15:41, 25 July 2008 (UTC)
So now one person disagreeing is "clear opposition"... *rollseyes*. Headbomb {ταλκWP Physics: PotW} 16:08, 25 July 2008 (UTC)
And your argument that since the title of the page isn't "list of standards ...", it means the table isn't a list, and shouldn't be subject to common sense guidelines for lists is nothing more than powder in the eyes. The title of a page dictates neither content (other than topic) nor style. Take a look at the List of baryons which does a lot more than simply "list baryons and give some properties" or the List of wild mammal species of Florida, which does a lot more than simply than "list the wild mammals of Florida and give pictures of them". If you want a list that doesn't start with "list of", that still follows the standard "identifier/properties" order then take a look at Coefficient of thermal expansion#Thermal expansion coefficients for some common materials or European emission standards.
And the reason the table needs more than one column for temperature and one column for pressure is that they are defined in more than one units and see what it means in other units. If we have more than one column, then we can bold or italicize the definition, making the table that much more usefull. Headbomb {ταλκWP Physics: PotW} 16:08, 25 July 2008 (UTC)
  1. ".. The intent was for the table to make a strong, visual impact on readers with the fact that many organizations had various standard conditions so that the point was made that there is no universal set of standard conditions. That visual impact is now lost because the table now just looks like a table of conversions. .. " (User:Mbeychok)
  2. ".. I think Headbomb's version has too many columns. I would only include the units that were actually used for defining these standards, .. " (User:Itub)
    Give the full quotes, not some misrepresentation. "IMO, the difference between the tables is not a big deal. However, I think Headbomb's version has too many columns. I would only include the units that were actually used for defining these standards, which would leave only deg C, deg F, atm, bar or kPa, and inHg.", or essentially the latest version of my table. Headbomb {ταλκWP Physics: PotW} 16:35, 25 July 2008 (UTC)
  3. ".. IMHO, the original table better achieved the purpose of illustrating the different standards. Having all the values converted isn't helpful in this case. .. " (User:Samw)
  4. ".. The new table is way too big, and has many superfluous fields. Having one temperature and one pressure in the list is enough, if the units have a link, recalculation can be done easily. The new table is way too big, and as said, this does not illustrate the different standards, it is a recalculation table. May I suggest reversion to the old table, and discussing things first (especially since there was already early in the process some comments on the new table)" (User:Beetstra)
  5. "I agree with Beetstra. Columns for temp, pressure, humidity and entity, in that order, with wikilinks instead of notes." (User:Kmurray)
  6. ".. I too liked the original version and I generally agree with the comments by Beetstra above. I think the visual impact was good and now that is largely lost. I too think the entity column should be at the right. Headbomb's argument that this makes no sense is just wrong, as it is OK to reference a fact after stating it. I see no reason to have a column for Farenheit. Keep it simple." (User:Bduke)

This whole argument started with one editor having objections, and now there are (in my counting) 6 (and certainly not one).

Also the three example tables that you now added to your list are exactly in the right way .. they are about the baryons, the animals and the thermal expansion coefficients of some common materials in the first place, respectively, and that is what is mentioned first in those tables. --Dirk Beetstra T C 16:20, 25 July 2008 (UTC)

Most of those comments were made before I chopped the Rankine, bar, and mmHg columns. And if you're going to argue that these table are well formated because they are about they start by listing the baryon names because it's about baryons, animal names because it's about animals, and coefficients names because it's about coefficients, then you'd also have to argue that this table should starts with standard names because it's about standards. I won't revert, but I certainly don't have to like this version. Nor do I have to like your accusations of "reverting against consensus" because people complained 'after I reverted. Headbomb {ταλκWP Physics: PotW} 16:28, 25 July 2008 (UTC)

No, I, and some others above, think that the table is about conditions. And at least 4 of the editors mention that only the defining or only one column for resp. temp, pressure and humidity is enough (in the remarks I cited in my last post). --Dirk Beetstra T C 16:35, 25 July 2008 (UTC)

Let's see: Bduke (an administrator), Beetstra (an administrator), Samw, Kkmurray and User:mbeychok have all said that the original version of the table was better than the revised version, and Itub thought that the revised version has too many columns. What does it take to convince someone that there is indeed a consensus? I agree completely with what Dirk Beetstra has done. GradEngineer (talk) 16:55, 25 July 2008 (UTC)
First, Bduke and Beetrstra could be the King and Queen of england for all I care, their opinions are not worth more than any other thinking person here. Second, I never claimed there wasn't consensus for switching back to the old version, nor to I dispute that switching back does not reflect consensus. I was accused of "reverting against consensus" by Beetstra and THAT is what I am disputing. At the time of my revert, only mbeychok opposed. One person being against does not constitute consensus, nor does me reverting to my version of things consitute reverting against consensus. As for these comments, most of them were made before I re-arranged the table, and it is rather presumptuous to suppose that disliking a previous version of things means disliking a newer version of things. Headbomb {ταλκWP Physics: PotW} 18:25, 25 July 2008 (UTC)
Does anyone have any idea what the most common use of this table is? Is it just as a demonstration of the many different standards there are? Or is it common that someone would use it to look up STP for a given standard? If it is primarily a demonstration of the many different standards then the table should use converted values (to SI units probably) so that apples can be compared to apples. (If the same Pressures and Temperatures are used but in different units for all of these systems can we really say they are different.) If on the other hand the table could be used by someone who is looking up a particular standard then the actual (nonconverted) values need to be given. I don't know how to satisfy both use cases without adding 2 more columns though. Finally, there is a cosmetic reason to keep the names of the standards at the end that may trump any practical reasons. Having them at the end allows them to be closer to the values allowing them to be easier visually aligned with the corresponding values. One could do the same for having the standard names as the first column only by right aligning the names which looks really bad IMO. My $0.02 worth. TStein (talk) 05:00, 26 July 2008 (UTC)
Earlier, Dirk Beetstra (an administrator) deleted the "Expand" template and it was reverted by Headbomb. So I am going to remove it again as per Dirk Beetstra's wishes. GradEngineer (talk) 16:55, 25 July 2008 (UTC)
As for the "Clarify" template, I am also removing that. "For a great many years" is perfectly clear. Anyone understands that. It is bit over the top to ask for the exact number of years, is it not? GradEngineer (talk) 17:06, 25 July 2008 (UTC)
For a great many years is unclear. I'm not asking for specific dates, but what does "a great many years" entail? Does it means from 1850 to 1875? Does it means from the scientific revolution until the 1930s? When did the pratice change? Hence {{clarifyme}}. Headbomb {ταλκWP Physics: PotW} 18:25, 25 July 2008 (UTC)
I hardly think it is worth a Clarify template, but "For a great many years" is the kind of sentence that begs the question. On one hand it is a small thing. On the other hand it is the type of thing that needs to be fixed to take a good article to great. If your goal is merely good then leave it, if your goal is greatness then it would be helpful to fix this. If this is the worst problem in the article then rejoice (and/or work a little harder to get it to the next level). TStein (talk) 05:00, 26 July 2008 (UTC)

How about a table with four columns for T and P? 1) T as defined in the standard (each cell will include the value with its unit); 2) P as defined (again with unit); 3) T in deg C, for ease of comparison and because it is an SI-compatible unit; 4) P in kPa or bar, for the same reason as 3). This setup serves both uses of the table and makes obvious why some standards chose odd-looking values, such as 101325 Pa. --Itub (talk) 09:03, 27 July 2008 (UTC)

The link for SPE ref is broken[edit]

Anyone got a new link? Headbomb {ταλκWP Physics: PotW} 04:09, 25 July 2008 (UTC)

"Clarify me" template now satisfied and removed[edit]

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)

ANR[edit]

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)

STP vs NTP[edit]

What is the difference between STP and NTP ? why? —Preceding unsigned comment added by Shivaaprs (talkcontribs) 05:25, 5 April 2010 (UTC)

This is a glaring omission. Half of the world uses NTP. 85.76.7.236 (talk) 19:10, 18 July 2010 (UTC)

EPA's STP[edit]

--George Kluney (talk) 20:25, 7 April 2010 (UTC) Propose the table be corrected to say 20 C instead of 25 C for EPA's standard temperature. Reference, cut ans pasted from CFR: "Title 40: Protection of Environment, PART 60—STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES, Subpart A—General Provisions § 60.2 Definitions. Standard conditions means a temperature of 293 K (68F) and a pressure of 101.3 kilopascals (29.92 in Hg)."

Molar volume of a gas[edit]

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)

Frustration[edit]

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 (talkcontribs) 21:23, 15 September 2010 (UTC)

Yet another ISO standard[edit]

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)

TPS Standard for american medical physics[edit]

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)

Missing criticism section[edit]

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)