View Question
Q: Pressure vs Temperature chart or Graph for Nitrogen (N2) ( No Answer,   12 Comments )
 Question
 Subject: Pressure vs Temperature chart or Graph for Nitrogen (N2) Category: Science > Physics Asked by: mrfixit1-ga List Price: \$2.00 Posted: 06 Jan 2005 19:22 PST Expires: 05 Feb 2005 19:22 PST Question ID: 453327
 ```I want a chart or graph that shows "Pressures vs Temeratures" for Nitrogen(N2). In other words I would like to find what the pressure is (in PSI or KPA) of nitrogen at -195.75C (or 77.36K). The chart or graph should include the full range of pressures for temperatures of (at least) -210C to 0C, in 10 degree increments if possible. I would accept TEMPERATURE in Celsius (C) or Kelvin (K) and PRESSURE in Pounds per square inch (PSI) or KiloPascals (KPA) or Pascals Some search words could be Vapor Pressure temperature curve, Graph, chart, thermodynamics, Nitrogen, N2, Refrigeration etc.``` Request for Question Clarification by pafalafa-ga on 06 Jan 2005 20:06 PST ```Your question seems to indicate that you're looking for a single value -- or a few discrete values -- for the pressure of nitrogen at a given temperature. Am I understanding you correctly? Most phase diagrams that I come across typically show a broad range of pressures for a given temperature. For instance, I've located a fairly broad phase diagram for nitrogen at low temperatures. The graph covers a temperature range of 0-140 Kelvin (with 10 degree increments). Pressure is measured in atmospheres on a log scale that ranges from 10^ -2 to 10^4 (1 atmosphere = 14.6959488 pounds per square inch). At a temperature of 77.36K, nitrogen would remain in a gas phase until a pressure of just about 1 atmosphere, would liquefy above that pressure until about 750 atmospheres, at which point it would solidify. Is that the sort of information you need? And if so, is the temperature range on the above-mentioned graph adequate to your needs? pafalafa-ga``` Clarification of Question by mrfixit1-ga on 06 Jan 2005 20:33 PST ```I am Looking for the whole graph so that I can find temp and pressure at any value I need, "atmosphers" is too broad a measurment and not accurate enough and would require to much conversion time for repeated testings,... I need the pressures from solid (-210C) to 0C, as you probably know the pressure of a gas is related to its temperature and I am adjusting pressures in a semi sealed vessel to obtain different temperatures within an insulated container used in experimentation for the freezing points of various mixtures``` Clarification of Question by mrfixit1-ga on 06 Jan 2005 21:00 PST `More search words ...saturated vapour pressure, (SVP)` Clarification of Question by mrfixit1-ga on 07 Jan 2005 08:31 PST ```Thanks bhushan, I went there but there is no where to find the temp and pressure for nitrogen, thanks very much for trying though!```
 There is no answer at this time.

 Subject: Re: Pressure vs Temperature chart or Graph for Nitrogen (N2) From: bhushi72-ga on 07 Jan 2005 01:26 PST
 ```Hi, I got a good site which does a lot of conversion and hopefully this will be helpful to you. http://www.digitaldutch.com/atmoscalc/index.htm Regards, Bhushan```
 Subject: Re: Pressure vs Temperature chart or Graph for Nitrogen (N2) From: mrfixit1-ga on 07 Jan 2005 08:32 PST
 ```Thanks for the time you spent on trying to help bhushi but there is no where to get the stats on nitrogen on that site.```
 Subject: Re: Pressure vs Temperature chart or Graph for Nitrogen (N2) From: capitaineformidable-ga on 07 Jan 2005 13:54 PST
 ```The first place I would always check for info like this is what's affectionately known as 'The Rubber Book'. Proper name is 'Chemical Rubber Company Handbook of Chemistry and Physics'. If you do a Google search for Chemical+Rubber+Company using IE its the first entry that comes up. I have checked out the table of contents on the web but I can't get inside the book to see if the data provided is what you need. The most likely sections seem to be: 6-91 Vapour pressure of fluids below 300K 6-129 Properties of cryogenic fluids Maybe you have checked this out already, if you havn't I hope it is useful to you. Regards capitaineformidable```
 Subject: Re: Pressure vs Temperature chart or Graph for Nitrogen (N2) From: hfshaw-ga on 07 Jan 2005 15:50 PST
 ```I'm not sure exactly what you want. Do you want: 1. The pressure-temperature curve along which nitrogen liquid coexists at equilibrium with nitrogen gas (the saturation vapor pressure curve); or 2. A means of calculating the rise in temperature resulting from the adiabatic compression of nitrogen gas. (Adiabatic means that no heat is allowed to enter or leave a system. A process occurring in a vessel with perfect thermal insulation would be considered an adiabatic process.)```
 Subject: Re: Pressure vs Temperature chart or Graph for Nitrogen (N2) From: capitaineformidable-ga on 08 Jan 2005 02:14 PST
 ```The confusing part, for me, is the meaning of 'Semi sealed'. It's difficult to understand how a SVP can be maintained in a system that is either adiabatic or isothermal in a partially open system.```
 Subject: Re: Pressure vs Temperature chart or Graph for Nitrogen (N2) From: mrfixit1-ga on 08 Jan 2005 09:01 PST
 `Thanks capitaineformidable I will try to check into that one`
 Subject: Re: Pressure vs Temperature chart or Graph for Nitrogen (N2) From: mrfixit1-ga on 08 Jan 2005 09:55 PST
 ```hfshaw: Just to clarify for everyone I will tell you what Im doing so that you can understand what I need: I am building a Very Low Temperature freezer that will be capable of temperatures below -100C My plan is to use liquid nitrogen and to allow it to feed into a steel container capable of containing high pressure, this steel container will be inside a small freezer. The steel nitrogen container will have a pressure regulater that will be ajustable so as to allow the nitrogen to evaporate at a pressure that I choose, that pressure adjustment will enable me to regulate the temperature of the nitrogen inside the steel container and it will get very cold, cooling the air inside the freezer. So I need to know the temperature of the nitrogen at different pressures so I can set the temperature of the freezer. For eveyones nerves: Rest assured that I will be taking all safety precausions that pertain to the risk of explosion of the steel container and the venting of the nitrogen so as to not allow the 78%/21% Nitrogen/oxegen air in the room to fall below a safe level.```
 Subject: Re: Pressure vs Temperature chart or Graph for Nitrogen (N2) From: mrfixit1-ga on 08 Jan 2005 10:09 PST
 ```I checked into that book capitaineformidable but as you say you cant get into it to see if it has the chart I need. Thanks for your help though, It did give me a few mor search words but nothing has come up with the graph I need.:-(```
 Subject: Re: Pressure vs Temperature chart or Graph for Nitrogen (N2) From: mrfixit1-ga on 08 Jan 2005 10:48 PST
 ```http://gaia.ecs.csus.edu/~reardonf/thermhtm/idgas.htm I am looking for graphs like this (second one down)```
 Subject: Re: Pressure vs Temperature chart or Graph for Nitrogen (N2) From: hfshaw-ga on 10 Jan 2005 00:24 PST
 ```Given your explanation, you are looking for data on the saturation vapor pressure curve. This can be obtained from the NIST databases at: Pressing the appropriate "button" on this page will allow you to toggle between a graphical and tabular view of the P-T data. You can also download the data in a tab-delimited file. You can pick a different spacing for the data points (still for N2) by starting over at Note that your proposal to use the boiling temperature of N2 liquid at different pressures to control the temperature of your system will only work between the temperatures of about 63 to 126 Kelvin. The critical point of N2 lies at ~126 K and ~34 bars; above this temperature, only one fluid phase exists, and there is no such thing as separate gas and liquid phases. Above this temperature, there is no such thing as "boiling", and you cannot control the temperature of your system in this way. I don't think you care about temepratures below 77K (and your apparatus won't let you control temperatures below this point anyway, because I think you are restricted to pressures above 1 bar.) Nevertheless, the triple point of N2 is at 63K and at 0.125 bars; at temperatures below this, N2 solid and N2 gas coexist along the sublimation curve. You could use this 2-phase equilibrium to define the temperature of your system, but the P-T curve will have a different slope than that of the boiling curve.```
 Subject: Re: Pressure vs Temperature chart or Graph for Nitrogen (N2) From: mrfixit1-ga on 10 Jan 2005 08:33 PST
 ```hfshaw: Thank you sooo much for that website! It is exactly what I want, Insidently I was at that site but did not have the "startover" web address that you provided and did not see all the other stuff. I am extreamly gratefull to you for taking the time to find that. I have been looking for 2 weeks. Take care and Have a good new year in 2005```
 Subject: Re: Pressure vs Temperature chart or Graph for Nitrogen (N2) From: mrfixit1-ga on 11 Jan 2005 17:07 PST
 ```HFshaw, Thank you for the information as well, It has made me change some of the ideas I was using and I have rethought the system, I will be useing more of a nitrogen drip system now.```