Talk:Thermal conductivity and resistivity

message: Please put less technical definitions within the first paragraph of all entries. I'm thinking 4th grade level would be appropriate, followed by more exact at 8th, 12th and then post-doc. 
In addition, a good example using house insulation and electrical schematic analogies would be appropriate.
In the section "First definition," the article states that "To physicists [1], thermal conductance is ..." and the footnote [1] points to the well-known and authoritative NIST Special Publication 811 which actually does not define or use the term "thermal conductance" anywhere.  This link is not really good evidence or corroboration of the assertion that there is a standard definition of thermal conductance.  (It is, however, a good place to find authoritative definit       ions of thermal conductivity, -insulance, -resistance, and -resistivity.)  Perhaps it should be moved?
Other semi-authoritative references like the CRC Handbook of Chemistry and Physics, 2002-203 edition don't define thermal conductance either.  (Although they do have conductivity.)
Does anyone have a more authoritative definition of thermal conductance as having the dimensions W / (m^2 K) (which can be more generally stated in terms of SI base units as:  kg / (K s^3) )  Preferably from an authoritative standards body, and not some individual's webpage or questionable textbook. 
I have a feeling that "thermal conductance" is a not-well-standardized term, if it's proper at all.  
I also find the phrase "to physicists" very questionable, as if physicists don't or shouldn't follow the SI but rather have their own standards.  (Last time I saw this in Wikipedia, it was a rather confused physicist arguing that "in physics," a pound was a measure of force, not mass.)  This phrase should probably be removed.
By the way, I'm interested in the right terminology because I'm building authoritative references in my programming language/calculating tool Frink.
: No, the NIST doesn't define thermal conductance, but as I recall it does define electrical resistance and conductance as reciprocals of each other. I felt I was on pretty safe ground assuming thermal conductance was the reciprocal of thermal resistance. Thats also how it works in "building trade" units. 
: I've since added a few more web references that look fairly reliable:  and for the future. The first says that the terms I've used - including thermal conductance - are in ISO 31-4:1992, Quantities and units - Part 4: Heat. Another new reference (, thermophysics FAQ 5) is much better for "builders" units.
: I've replaced "To physicists" with "For general scientific use". I would have put "in SI units" or something similar, but I think maybe only some of these units are defined as part of the SI, while others are derived. After all, "bulider's" thermal resistance is loosely "in SI" if it's expressed as (K m^2)/W. And for SI we should really refer to the BIPM rather than the NIST.
:Andy G 18:25, 10 Sep 2003 (UTC)
thread_title:  Definitions 

message: The books I've read on this subject use k or lowercase kappa instead.--Tenfour 23:00, 3 August 2005 (UTC)
replies: text: Symbol k is used for almost everything and kappa is hard to distinguish from it. So I believe lambda is more definite here. It is used in many European books.  Adams13 (talk) 07:11, 4 July 2008 (UTC)
thread_title: lamda?

message: I came across this information for the thermal conductivity of various material and the author cites the information came from a book by Hugh D. Young. The site is http://hyperphysics.phy-astr.gsu.edu/hbase/tables/thrcn.html
  LDCorey 05:50, 21 February 2006 (UTC)
thread_title:  Source for values 

message: This article says 0.005W/Km, aerogel article says 0.0155W/Km. --njh 01:25, 29 March 2006 (UTC)
replies: text:  Aerogel article contained no citation for 0.015W/Km value. I have changed that article and added referece. Hopefully future changes will include citations and we can evaluate values based on the quality of the source.
=== Querying aerogel's record low thermal conductivity ===
As a follow-up to the preceding comment, could an expert please verify/comment on the extremely low claimed thermal conductivity:
0.003 W/m.K - best insulator in Guiness Book of World Records - for SEAgel. (The SEAgel Wikipedia page doesn't repeat this claim.)
The explanation given for it being a good conductive insulator is:
"Silica aerogel is a good conductive insulator because silica is a poor conductor of heat" Yet a Google search returns an unremarkable thermal conductivity for silica, as might be expected: http://www.azom.com/details.asp?ArticleID=1114 reports 1.3 (1.4) W/m.K for quartz (fused silica).
Since the aerogel is mostly air, a reasonable expectation would be a heat conduction value
similar to air, as I understand is the case with the best (i.e. closed cell) insulators based on air. This article states the conductivity of air to be 0.0262 W/m.K and the Engineering Toolbox, http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html, gives it as 0.024 as well as giving a generic entry "Insulation materials 0.035 - 0.16".
If I could hazard a guess, would it be possible that someone somewhere has inadvertantly stuck
in an extra zero in the the SEAgel conductivity and this error has been propagated? (Compare with the iron content of spinach, which I understand used to be a factor of 10 too high in many nutrition tables.) Or could there instead be some valid physical reason why SEAgel does an order of magnitude better than its dominant constituent, air?
Expert comments would be much appreciated ...
Thanks, 202.74.220.117 02:26, 30 March 2006 (UTC)

text: The change was by Az7997
(cur) (last)  08:20, 30 March 2006 Az7997 (→Silica aerogel - changed thermal conductivity value to CRC value and ADDED REFERENCE, WHAT A CONCEPT!!!)
My understanding is the aerogel is comparable with closed cell (perhaps a factor of 2 better). --njh 02:33, 30 March 2006 (UTC)

text: I wrote an explanation about why aerogel is a good insulator (it is not because it is made of silica), but this NASA web page explains it better. NASA did not invent aerogel, but they developed it further. 0.017 W/mK is a frequently quoted number. It is often rounded to 0.02 W/mK. I think that sometimes it is mistakenly written as 0.002 and 0.003. One company that makes aerogel claims that it has gotten it down to 0.011-0.013. An aerogel fact sheet by NASA says that it ranges from 0.016 to 0.03. Part of the variance depends on what properties are wanted for the aerogel. For example, if you want it to be more rugged, you might have to increase thermal conductivity. Some NASA aerogels are significantly higher in thermal conductivity because of their application. I recommend using the values from NASA, either 0.016 or as a range 0.016 to 0.03. -- Kjkolb 04:00, 30 March 2006 (UTC)
thread_title:  aerogel TC? 

message: As a follow-up to the preceding comment, could an expert please verify/comment on the extremely low claimed thermal conductivity:
0.003 W/m.K - best insulator in Guiness Book of World Records - for SEAgel. (The SEAgel Wikipedia page doesn't repeat this claim.)
The explanation given for it being a good conductive insulator is:
"Silica aerogel is a good conductive insulator because silica is a poor conductor of heat" Yet a Google search returns an unremarkable thermal conductivity for silica, as might be expected: http://www.azom.com/details.asp?ArticleID=1114 reports 1.3 (1.4) W/m.K for quartz (fused silica).
Since the aerogel is mostly air, a reasonable expectation would be a heat conduction value
similar to air, as I understand is the case with the best (i.e. closed cell) insulators based on air. This article states the conductivity of air to be 0.0262 W/m.K and the Engineering Toolbox, http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html, gives it as 0.024 as well as giving a generic entry "Insulation materials 0.035 - 0.16".
If I could hazard a guess, would it be possible that someone somewhere has inadvertantly stuck
in an extra zero in the the SEAgel conductivity and this error has been propagated? (Compare with the iron content of spinach, which I understand used to be a factor of 10 too high in many nutrition tables.) Or could there instead be some valid physical reason why SEAgel does an order of magnitude better than its dominant constituent, air?
Expert comments would be much appreciated ...
Thanks, 202.74.220.117 02:26, 30 March 2006 (UTC)
replies: text: The change was by Az7997
(cur) (last)  08:20, 30 March 2006 Az7997 (→Silica aerogel - changed thermal conductivity value to CRC value and ADDED REFERENCE, WHAT A CONCEPT!!!)
My understanding is the aerogel is comparable with closed cell (perhaps a factor of 2 better). --njh 02:33, 30 March 2006 (UTC)

text: I wrote an explanation about why aerogel is a good insulator (it is not because it is made of silica), but this NASA web page explains it better. NASA did not invent aerogel, but they developed it further. 0.017 W/mK is a frequently quoted number. It is often rounded to 0.02 W/mK. I think that sometimes it is mistakenly written as 0.002 and 0.003. One company that makes aerogel claims that it has gotten it down to 0.011-0.013. An aerogel fact sheet by NASA says that it ranges from 0.016 to 0.03. Part of the variance depends on what properties are wanted for the aerogel. For example, if you want it to be more rugged, you might have to increase thermal conductivity. Some NASA aerogels are significantly higher in thermal conductivity because of their application. I recommend using the values from NASA, either 0.016 or as a range 0.016 to 0.03. -- Kjkolb 04:00, 30 March 2006 (UTC)
thread_title:  Querying aerogel's record low thermal conductivity 

message: Thanks to njh and Kjkolb for very helpful replies to my query.
As further information,
Google returned a reference http://eetd.lbl.gov/ECS/aerogels/satcond.htm
that quotes a typical total conductivity of 0.017 W/m.K for silica
aerogels (i.e. the original value in the table that agrees well with
the 0.016 recommendation of Kjkolb, and that was replaced by the value
0.003 W/m.K that I query). This is actually a well written and informative article
on the thermal conductivity characteristics of aerogels and is part of
an excellent more general write-up on aerogels,
http://eetd.lbl.gov/ECS/aerogels/satoc.htm ,
that I would recommend as a reference for http://en.wikipedia.org/wiki/Aerogel .
At the risk of complicating this discussion,
The thermal article also hints at another way that a thermal conductivity
of 0.003 W/m.K might conceivably have been reported: they themselves report a similar
minimum value for a silica aerogel with added carbon of ~0.0042 W/m.K .
Crucially, however, this is by *evacuating* the aerogel - which is clearly
not legitimate for a thermal conductivity table. (To show how absurd this
would be, the record-holder for insulating materials in the Guinness Book
of Records would then have to be for the trace gases in an ultra-high vacuum
and that thermal conductivity would be dominated by radiative transfer and would
depend on the temperature and emissivity of the vacuum walls rather than
the thickness of the vacuum - in short, the coefficient of a total thermal
conductivity with units of W/m.K ceases to make much sense for vacuum
environments.) To give a second recommendation, I agree with Kjkolb that
the entry in the
table could be 0.016 or 0.017 W/m.K for a "typical silica aerogel".
Or instead it could be left out of the table since the table doesn't yet
even include such common and important substances as water: the value for
water is 0.58 W/m.K, given in
http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html .
This is a good comprehensive reference and my third recommendation is to
add this to the general references for this topic,
http://en.wikipedia.org/wiki/Thermal_conductivity .
Regards, 202.74.218.111 11:32, 30 March 2006 (UTC)
thread_title:  Further on querying aerogel's record low thermal conductivity 

message: The name "K-Value" is also used to describe molecular size of polymers . --Jak123 18:18, 18 April 2006 (UTC)
thread_title:  Disambiguation 

message: It would be helpful to insert a row for Beryllium oxide in the table of thermal and electrical conductivities. DFH 20:55, 23 November 2006 (UTC)
thread_title:  Beryllium oxide 

message: I hope this is an obvious merge, and I will add a redirect to Thermal resistance, unless there is any resistance to this.+mwtoews 21:49, 24 November 2006 (UTC)
replies: text: Right-O. Done. +mwtoews 00:15, 26 November 2006 (UTC)
thread_title:  Merge [[Thermal resistance]] to [[Thermal conductivity]] 

message: Most diamonds (with some exceptions) are electrical insulators (see diamond article). This article says that diamond is an electrical semiconductor. —The preceding unsigned comment was added by 129.241.94.20 (talk) 09:59, 15 December 2006 (UTC)
thread_title:  Diamond and electrical semiconductors. 

message: I've written my rant next to other relevant discussion above.  I'm adding this note at the bottom of the talk page because I expect it's where people will look to see why the tag was added. --ToobMug 02:15, 23 January 2007 (UTC)
thread_title:  Cleanup-list Tag 

message: In the list, iron is marked as the material used in power lines. AFAIK, no power lines (this side of ~1930?) are of iron or even stainless steel, but rather aluminium. Correct?
81.233.228.251 18:52, 6 February 2007 (UTC)
replies: text: High Voltage (132kv and above) power lines are steel cored with an aluminium shroud. The steel core is needed to provide strength due to the spans and temperatures involved.  —Preceding unsigned comment added by 90.221.179.103 (talk) 09:14, 21 August 2010 (UTC)
thread_title:  Iron - Power lines? 

message: I brached off the section list of thermal conductivities into its own article. What do you think? --Tunheim 12:14, 9 February 2007 (UTC)
replies: text: I fixed the link to the 404. Otherwise I think you've got your units mixed up. Please confirm them. Wizard191 (talk) 21:08, 18 May 2011 (UTC)
thread_title:  [[List of thermal conductivities]] , and value for stainless steel 

message: So I was searching for "k-value" as the spring constant used in Hooke's law, and came to this page instead.  I just put one of those "if you meant this go here" things on the top, but maybe there should be a disambig. page for "k-value"? Nirvelli 19:36, 6 September 2007 (UTC)
thread_title:  Disambig. for k-value 

message: The H= part of the first equation should be removed.  It is used only there, it is not defined, its units are not given, there is no intuitive explanation of its usefullness.  The article on heat conduction does not introduce an H.  Let it be gone.  blackcloak (talk) 06:40, 16 August 2008 (UTC)
thread_title:  Why is H introduced in intro? 

message: what is the definition of thermal resistivity? 
what is the best measurement method  —Preceding unsigned comment added by 92.238.156.233 (talk) 23:00, 18 September 2008 (UTC)
thread_title:  what is the definition of thermal resistivity 

message: The thermal conductivity listed for Sapphire in Thermal conductivity seems to be extraordinarily high: "CRC Handbook] reports a thermal conductivity of 2.6 W/(m·K) perpendicular to the c-axis at 373 K, but 6000 W/(m·K) at 36 degrees from the c-axis and 35 K"  6000 W/(m·K) is nearly three times that of diamond.  Diamond, I understand, has the highest conductivity.  The temperature comparison 373 K, and 35 K are odd as well.  I checked the CRC Handbook of Physics and Chemistry 62nd edition (old) and the web and did not find anything close to 6000 W/(m·K).  The highest I found was about 45 W/(m·K) at about 400 K.  
The 6000 appears to me to be a mistake.  Maybe a dropped decimal point 60.00 W/(m·K)?  If nobody can find a reference, perhaps this should be deleted?  Also will add a  Jim1138 (talk) 00:55, 27 October 2008 (UTC)
replies: text: Replaced with a different quote. Sebastian (talk) 05:53, 17 November 2008 (UTC)
thread_title:  Thermal conductivity of Sapphire 

message: I realize that my putting a merge template on both articles may have started this discussion off on a wrong foot. I did not mean (or at least do not mean anymore) that the two articles necessarily should be merged. I do think that we have a problem that concerns the overlap between both of these articles. I don't have much time now, but I plan to make a table here within three days that graphically explains the problem I see. Please hang on! — Sebastian 05:51, 9 December 2008 (UTC)
thread_title:  Restating the problem 

message: I nead the thermal coductivity of brass  —Preceding unsigned comment added by 94.99.99.162 (talk) 17:15, 22 May 2009 (UTC)
thread_title:  Brass ? 

message: I made swimwears w/ Plastic trim (Acrylic), and customer claimed 2nd degree burn from it.
How is it possible? I thought it is safe enough because it is plastic. Please advise.  —Preceding unsigned comment added by Sudolisa (talk • contribs) 18:41, 30 June 2009 (UTC)
thread_title:  Plastic trim  

message: Please someone who understands thermal conductivity bring the article inline with MOS:MATH#Multiplication_sign. I think its suppose to be W/(m×K), that is × not a manually typed · character. Thanks.  —Preceding unsigned comment added by 99.155.197.82 (talk) 02:16, 1 June 2010 (UTC)
thread_title:  Multiplication or Dot Product? 

message: The page says
"heat transfer coefficient = k/L, measured in W·K−1·m−2 ... The heat transfer coefficient is also known as thermal admittance"
I don't think that's the correct definition of admittance. It's used in practice to describe heat flow under non-steady state conditions, just as electrical admittance, while k/L is a steady-state value. I've posted one reference below and will look for a better one. But if anybody thinks the current statement is correct, could they please post a reference. 
http://www.sciencedirect.com/science/article/B73HD-47YMY4S-2H/2/d56fa17bd3ef7540e499b077433ea55a
The thermal admittance of layered walls  M.G. Davies
"A procedure is developed for computing thermal admittance, the ratio of the sinusoidal component of heat flux at the surface of some building construction to the corresponding temperature variation there". 131.111.85.79 (talk) 09:44, 18 June 2010 (UTC)
thread_title:  Admittance 

message: The transmittance of 7.5 nm of gold, copper, and silver films into Si and GaAs is nearly 60% in the middle of the visible spectrum (H.J. Hovel, "Transparency of thin metal films on semiconductor
substrates", J. Applied Physics, 47:11, 4968-4970, Nov. 1976).  This would seem to suggest that photons in the visible spectrum have a mean free path of around 15 nm in these metals.  At room temperature these metals will radiate at much greater than visible wavelengths, closer to 10 μm.  How much does the mfp for photons in these metals decrease at these longer wavelengths of radiation?  And how does this compare with the mfp for phonons in these metals at the same temperature?
The reason I ask is that I've been wondering how heat flux in highly conductive (both thermally and electrically) metals such as these should be apportioned between mechanical and EM transport mechanisms.  Is this well understood, at room or any other temperatures?  So far I've found essentially zilch online about this, but perhaps I'm just giving Google the wrong phrases to search on.  This Wikipedia article would seem to imply there is no significant radiative component in thermal conduction.  If this is true it would be nice to understand why since it doesn't seem obvious.  --Vaughan Pratt (talk) 06:30, 31 August 2010 (UTC)
replies: text: The talk page of this article is meant to be about improvements to the article. As such, you aren't likely to get any answers here; try the WP:REFDESK. Wizard191 (talk) 13:42, 17 April 2011 (UTC)
thread_title: How much of thermal conductivity in metals is due to radiation?

message: The thermal conductivities of liquids are notably low relative to solids.  The thermal conductivity of water (0.6) is higher than almost all other ordinary liquids, and almost any additions to water (salt etc) lower the thermal conductivity.  Why?-96.237.79.6 (talk) 03:21, 27 September 2010 (UTC)
thread_title:  Liquids 

message: There are two different measurements (I'll give metric and IP units first, and then stick to metric)
One is in units W/(m⋅K) [Watts/(meter⋅Kelvin)] or BTU/(h⋅ft⋅F) [British Thermal Unit/(hour⋅foot⋅Fahrenheit)]
The other is similar, but W/(m²⋅K) or BTU/(h⋅ft²⋅F).
The fact that the units are different means that they refer to different properties of a material (the difference may just be that one value is thickness-dependent and one is thickness-independent).
The reason I noticed this is that the first paragraph mentions thermal conductivity in the window industry and says that it is called U-factor. The article begins talking about conductivity as something with units of W/m⋅K, but U-factors definitely have units W/m²⋅K - so not the same thing, right?
Alex Crikey (talk) 23:01, 4 March 2011 (UTC)
thread_title:  Thermal Conductance or Conductivity 

message: I corrected the table's value for unfilled epoxy. The corresponding graphic, http://en.wikipedia.org/wiki/File:Thermal_conductivity.svg, also needs an update as a result - the two are now out of sync.
Microfirmware (talk) 21:12, 21 April 2011 (UTC)
replies: text: Fixed. Wizard191 (talk) 01:38, 28 April 2011 (UTC)
thread_title:  Updating http://en.wikipedia.org/wiki/File:Thermal_conductivity.svg? 

message: This is a physical reason for the greater sensitivity of electronic thermal conductivity to energy dependence of density of states and relaxation time, respectively.
:Could this perhaps be phrased a bit clearer? I'm having a hard time figuring out what exactly is being said, like greater sensitivity compared to what, and why the "respectively" at the end? 84.197.178.75 (talk) 09:35, 7 March 2012 (UTC)
thread_title:  Say what? 

message: Seriously, this is not ph.d. science wiz wikipedia, this is regular wikipedia. Stop expecting regular people to know what "M1L1T−3Θ−1" means without defining the variables! Why would you not want to define them in the first place? That should've been the first thing that came to your mind after typing that, or did you think that equation was common sense. I don't know where I can get my hands on the book you referenced. Not everyone is literate in your subject, and how do you expect them to become literate if you don't provide the definitions in a way we can understand.
I'm not afraid of big words. In fact I urge you to use them, but for the love of God, DEFINE them, that and variables in equations that are posted. Don't expect that I already know them. And no I'm not being lazy I tried to figure it out on Google, it's harder than you think.98.209.57.51 (talk) 21:47, 18 November 2012 (UTC)
replies: text: For the answer to your question, read Dimensional analysis. - David Biddulph (talk) 23:36, 18 November 2012 (UTC)
thread_title:  NEEDS MORE DEFINITIONS! 

message: The first graph that shows values of thermal insulation, what is on the y-axis? Seriously, not labeling both axes is very poor design. I also started a talk page on that graph's file page with the same question. DrZygote214 (talk) 09:14, 12 October 2016 (UTC)
thread_title:  What is on the y-axis of the graph? 

message: Most of the Electronic thermal conductivity section is about materials with a particular electronic structure : "if the electron density of states in the material is close to the delta-function, the electronic thermal conductivity drops to zero" - but does not say if they are common or important or otherwise significant. Which materials have this property ? - Rod57 (talk) 15:47, 11 February 2018 (UTC)
thread_title:  Which materials have eDOS close to the delta function 

message: Article mentions [non]metals with their electrical conductivity ; What about graphite/graphene (non-metallic yet electrically conductive) - Should they be discussed as if they were metals ? - Rod57 (talk) 15:58, 11 February 2018 (UTC)
thread_title:  Nonmetals or insulators 

message: Article says there are two mechanisms in 'metals' or electrical conductors : free electrons and lattice vibrations (phonons) - but what is their relative contribution to the thermal conductivity, in general or in specific materials ? - Rod57 (talk) 16:03, 11 February 2018 (UTC)
replies: text: No mention of thermal hall effect which says "Measurements of the thermal Hall conductivity are used to distinguish between the electronic and lattice contributions to thermal conductivity." (no source given) - Rod57 (talk) 19:30, 11 February 2018 (UTC)
thread_title:  Electrons vs lattice 

message: I wrote this section recently. I see someone edited it to indicate it needs references. Although I have several, I don't have one explicitly for the equation. Here's a reference ( https://www.saylor.org/site/wp-content/uploads/2011/04/Thermal_conductivity.pdf ) See the equation on pg6. It is identical, but just uses slightly different terms. I'm going to add this as a reference, but I don't know how to add references very well, so if you see I didn't do it quite right, just fix it for me, please don't undo my work entirely. It is based on sound physics and principles. Thanks. ERCaGuy (talk) 00:06, 8 August 2018 (UTC)
replies: text: Done! I just added the reference and explained the alternate form of the equation to show they are identical. ERCaGuy (talk) 00:45, 8 August 2018 (UTC)
replies: text:  That source is a piece of Wikipedia. We certainly cannot have that per obvious wp:CIRCULAR. I have undone the edits to the article per wp:UNSOURCED. - DVdm (talk) 17:45, 8 August 2018 (UTC)
thread_title:  "Conversion from specific to absolute units, and vice versa" section "needs references" 

message: It's great to have a section on lattice waves, but the current presentation is too technical. A note to this effect has been added. The two main reasons for this assessment are 1) too much detail, and 2) too much technical terminology. Comments welcome. MaxwellMolecule (talk) 14:45, 17 January 2019 (UTC)
replies: text: The section perhaps should be called lattice waves in dielectric solids to try to justify its placement with molecular origins ? It's a large sections and could perhaps be split out into a separate lattice wave modelling of thermal conductivity in dielectric solids? - Rod57 (talk) 10:09, 20 August 2023 (UTC)
thread_title: Lattice waves

message: Below about 10 K the th-c metals of metals tends to linear in T, but non metals (semiconductors & insulators) (eg Si, Ge, quartz, sapphire ...) show it tending to T^3 (Temp cubed). Article should mention this and say what theories explain. - Rod57 (talk) 09:44, 20 August 2023 (UTC)
thread_title:  No mention of cubic variation of th-cond with low absolute temps for non-metals 

message: There is a move discussion in progress on Talk:Thermal resistance which affects this page. Please participate on that page and not in this talk page section. Thank you.  —RMCD bot 13:35, 2 October 2023 (UTC)
thread_title:  Move discussion in progress 

message: The dimension of Thermal resistivity, in the lower gray box, appears as "LMT-3Θ-1".
This is quite clearly incorrect, as it is the same dimension as Thermal conductivity, while it should be the inverse.
The Thermal resistivity wikidata item, used as source of the Dimension field, contains the right dimension.
But in the usage page for resistivity only the reference to conductivity appears.
Before attempting to edit (putting a static string instead of the wikidata reference), I'd like to know whether this is some kind of bug or a limitation in instantiating templates that refer to wikidata, or I am missing something obvious.
Exactly the same happens on the Thermal conductance and resistance page.
Note: I've tried with Firefox and Edge browsers in Windows and Android. 92.34.17.5 (talk) 16:53, 2 November 2023 (UTC)
thread_title:  Dimension of Thermal resistivity 

message: The dimension(s?) of thermal resistivity is (are?) incorrect.  It looks as though they have been copied from thermal conductivity.  I can't find this in the source code so I can't proposes a correction. NeilAzby (talk) 20:21, 6 November 2023 (UTC)
thread_title:  Thermal resistivity