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"...relates the attenuation of light to the properties of the material through which one substance like light, neutrons or host rarefied gases is traveling"
Is light now a substance?
It's not clear what the defining characteristics are of the class "substance like light, neutrons or host rarefied gases". Would whey (traveling through cheesecloth) count?
So if you have neutrons passing through a material, light is attenuated? What light is affected?
I realize that it's difficult to explain highly technical subjects to fourth-graders, but it would make this highly important page MUCH more useful if was written clearly, instead of simply tossing keywords on the page, without bothering to ensure the sentences make sense. 12.193.238.99 ( talk) 23:08, 20 September 2014 (UTC)
Dr Bob, I'm not sure where you are from...but google beer lambert and mostly everyone in our World (Earth) uses A = Δ b c.
Dr Bob...the reason we introduce other variables is because not everyone is like dr bob and some of us use different variables. : )
Yes, but wouldn't it be better if we used standard IUPAC nomenclature "A = Δcl" instead?
Does this make sense: "If concentration c is expressed in moles per unit volume, α is a molar absorptivity usually given in units of mol cm-2?" Shouldn't it say in units of cm2 mol-1? Srnec 04:30, 16 February 2006 (UTC)
Am I the only one who feels the picture is unsuitable? The rhodamine is fluorescing - the light that is diminishing with greater pathlength is not the incident beam but light arising from the absorption of the incident beam. that's adding a whole new layer of confusion - could someone post a similar picture with a non-fluorescing material? Or a picture of a pane of glass from the from and side, showing how the increased pathlength leads to increased absorption resulting in the glass looking green from the side â Preceding unsigned comment added by 86.46.54.236 ( talk) 16:30, 6 July 2012 (UTC)
This picture should be indeed removed. The figure illustrates fluorescence and not absorption! Trelam ( talk) 19:48, 11 February 2015 (UTC)
I think the article should more explicity explain the relationship beween absorbance and transmittance, or point to an article that does cover this. It is sort of in the article already (Ii/Io), but that wouldn't be clear to the uninitiated. ike9898 17:43, 14 March 2006 (UTC)
I've added a simple derivation of the law, with an explanation of the problem at high concentrations. I've used the notation in the previous section, although I do not like it - for reasons that others have already mentioned. It seems we're married to the notation used in the figure, and this is unfortunate. ike9898 - I added a line defining transmittance after seeing your comment.
This is actually my first contribution, and my first attempt at LaTex. The fonts don't look quite right, and I would welcome anyone attempting to clean it up.
Axewiki 12:51, 13 September 2006 (UTC)
This looks a lot like the few other derivations I was able to find on the web.... neffk ( talk) 06:23, 21 November 2009 (UTC)
I left a nice clean derivation on this website in 2006, and came back now only to find it replaced by a messy cluttered derivation, wholly unsuitable for my students. Symbols are unnecessarily complex, difficult to read, and in at least one case, undefined. Rather discourages efforts to edit ... Axewiki ( talk) 03:19, 13 July 2015 (UTC)
Beer-Lambert law is a conection of Beer law and Lambert law, so in the very first line is untrue information. Both are now historical, but...
So if you have time to fix it, please do it. Probably it will need a minor changes in biographical articles about Beer and Labbert. -- 82.139.42.165 23:16, 25 September 2006 (UTC)
Precise references are needed to back up the history section, particularly with regards the role of Bouguer. Ga2re2t 17:00, 25 October 2007 (UTC)
I found the equation (4th equation from this article) to be confusing
I reasoned, since alpha has various sets of units (see paragraph below) so must k, yet the way k is derived in the article Extinction coefficient indicates that k has only one set of units, and if the equation above is correct alpha must have only one set of units, which comes back to my point that I am confused.
So I wanted to ask/plead that someone who knows whats going on, amend either the paragraph below quoted from the article or the equations, such that the whole thing is less confusing. Or at least so that the units for the equation are clear.
"The units of c and α depend on the way that the concentration of the absorber is being expressed. If the material is a liquid, it is usual to express the absorber concentration c as a mole fraction i.e. a dimensionless fraction. The units of α are thus reciprocal length (e.g. cmâ1). In the case of a gas, c may be expressed as a density (units of reciprocal length cubed, e.g. cmâ3), in which case α is an absorption cross-section and has units of length squared (e.g. cm2). If concentration c is expressed in moles per unit volume, α is a molar absorptivity (usually given the symbol Δ) in units of molâ1 cmâ2 or sometimes L molâ1 cmâ1." â Preceding unsigned comment added by 139.67.205.181 ( talk)
Something is wrong with the first section (2007-03-22). There's a missing ln(10) somewhere. This is obvious, since A is defined in terms of log10, but the rest of the constants are non-log quantities. I'm not sure where it goes, though. âThe preceding unsigned comment was added by 192.249.47.9 ( talk) 19:04, 22 March 2007 (UTC).
A user named "Anarotram" deleted a section of the derivation I composed and left the message "I deleted the last comment that appears entirely wrong. The requirement on the slab thickness dz is not involved in the integration step. I deleted the last comment that appears entirely wrong. The requirement on the slab thickness dz is not involved in the integration step.". There is no record of this user making any other edits to Wikipedia pages.
This comment does not explain what Anarotram believes is wrong. The integration is clearly over dz, so the comment is puzzling. Also, the sentence beginning with "The requirement ..." is fractured English, so I'm not even sure what it means.
The effects of error in this assumption is a basic spectroscopic phenomenon that I have students prove to themselves when they first start working with a spectrophotometer. The phenomenon is real, and has a very simple basis. If Anarotrim has another explanation it should be entered into the discussion before a widely accepted explanation is merely deleted. Axewiki 21:13, 18 August 2007 (UTC)
IUPAC recommends that Δ be called the molar (decadic) absorption coefficient. See
[1],
[2], and especially
[3].
â DIV (
128.250.204.118 08:20, 7 September 2007 (UTC))
I am under the impression that absorptivity should not redirect to this page.
Absorptivity, as it pertains to heat transfer and infrared radiation/optics, is a simple ratio of the irradiation absorbed over the total irradiation. Where, the total irradiation is the radiative flux incident to a surface, both from direction emmission and reflection from all other surfaces in a system. Additionally this unit is dimenssionless and is also given by the greek letter alpha.
The strict definition of absorptivity in infrared radiation is completely analagous to reflectivity and the emissivity.
Furthermore, several wikipedia pages reference and link to this page on absorptivity however they are obviously refering to the dimensionless absorptivity and not to the absorbance that this article discusses.
I could and probably will fix this inconsistency, by the end of the year hopefully, with the addition of a start up article on absorbtivity.
I would appreciate feed back on the discussion page or my talk page. The Lamb of God ( talk) 16:32, 17 June 2009 (UTC)
Absorptivity is only equal to the emissivity in an isothermal inclosure, that is, an object in thermal equillibrium. So, in regards to black bodies, the absorptivity is always equal to the emissivity and both have a value of 1.
This is given in Kirchoff's Law. And as you have probably discovered the absorptivity refered to in Kirchoff's Law and the emissivity articles link to this article.
I am working on expanding the Kirchoff's Law page also, (which is where the issue started in the first place.) So, in conjuction I will see what I can do.
In the mean time I do not know what absorptivity should link too???
I may simply create a 1 paragraph article in the short term and direct it there or follow your suggestion and do the 1 paragraph in emissivity. The Lamb of God ( talk) 14:47, 18 June 2009 (UTC)
Please use the terms Naperian and decadic to distinguish between natural and common logarithms. This is what IUPAC does. IUPAC generally tries to reconcile differing notations between different fields. I've personally never seen used in a decadic system. Also, Naperian vs decadic doesn't really have anything to do with the analyte's state of matter. The solid phase isn't even mentioned! Naperian and decadic definitions are just a matter of different fields having different traditions. 128.146.32.223 ( talk) 01:54, 2 September 2009 (UTC)
"Please use the terms Naperian and decadic to distinguish between natural and common logarithms." These two comments look like an example of absurdly preferring gobbldegook over plain language. If you mean common logs just say that, and the same for natural logs. There is nothing wrong with simply saying what you mean... âPreceding unsigned comment added by 82.32.49.157 ( talk) 11:13, 2 February 2011 (UTC)
This article is ridiculously verbose. There are way too many examples, at most one example is needed. In particular the "Chemical Analysis" and "BeerâLambert law in the atmosphere" sections could simply be deleted. The discussion about different units is unimportant to a general audience. (As a matter of fact, it can be highly confusing to specialists.)
I've tried googling for it (define: aborbance) and I've tried m-w.com--neither one defines it. If I search for aborbance, I find lots of references to it (over a 1000, iirc), but my guess they are all careless misspellings.
I was going to correct the spelling, but I have just a little bit of doubt. (If someone does correct it, search the page, I think there is more than one occurrence.)
Rhkramer ( talk) 11:40, 2 November 2010 (UTC)
I have edited the Prerequisites paragraph, presenting the 2 conditions which were originally stated under item (2) as separate requirement (now 2 & 3, the remainder being renumbered up to 6). I have no argument with these requirements. But, when they are stated explicitly, which is a good thing to do, it is clear that the illustration (which involves fluorescence) cannot be a good example of the law in action, since it transgresses condition (3) "no scattering" and also condition (6) "no influence on medium". For the sake of consistency, either a better illustration should be found, or the reasons for ignoring these transgressions (change in wavelength - the B-L law can be applied to the original green light only) should be given. Dr Andrew Smith âPreceding unsigned comment added by 82.32.49.157 ( talk) 11:07, 2 February 2011 (UTC)
I'm a third year pharmacy student, and I've done my first year of basic chemistry, and even I find it difficult to follow this page. I can't imagine how this looks to person with a non-science background. I of all people understand the need to explain things properly, but this page seriously needs to be simplified somehow. I've not seen anything resembling "A = Δ b c", nor do I think I have seen a mentione of Δ1%. Seriously, please do something about this Chairman Xi ( talk) 05:31, 10 March 2012 (UTC)
It is implicit in the law that shadowing must occur. This is because the incident intensity on the infinitesimally thin slab is dependent on the output intensity of the slab before. If no shadowing occurred, there would be no need to perform calculus and the entire slab would be considered as one. Putting this falsehood back in the article is lying to people. If you think better wording should be used, then try to word it better, but leave in the fact that the shadowing is required for the derivation of the law to hold true (which actually means the law breaks down at low concentration/pathlength/extinction coefficient) not high). Black.jeff ( talk) 20:30, 17 October 2013 (UTC)
References
I would like to point out that an editor of the French article has deleted the section on the atmosphere as "totalement faux" (totally false). When I asked for further explanation on the talk page, that editor and one other explained that the equation given does not apply to diffusive media such as the atmosphere. See discussion in French at fr:Discussion:Loi de Beer-Lambert#Suppression de section Loi de Beer-Lambert dans l'atmosphĂšre.
This raises the question of whether the section should be removed from the English article also. I don't know enough to judge whether the objections are valid. Perhaps those editors who are more expert in optical theory could read the French discussion and comment. Dirac66 ( talk) 00:59, 31 December 2016 (UTC)
I ended up watching some youtube videos explaining the law, which is a LOT simpler than the whole article there.
I have no problem with anyone explaining things in a complicated way per se, but wikipedia should also teach people; and from this point of view, the article is worded and structured in a WAY too complicated manner. Not everyone is a maths genius - the article was clearly written by physicists mostly. 2A02:8388:1603:CB00:3AD5:47FF:FE18:CC7F ( talk) 11:57, 10 December 2017 (UTC)
It occurred to me answering a question on Mass attenuation coefficient related to lambda, that lambda is commonly used for absorption coefficients (in the numerator of the exponent), though not in this article. (Maybe more in physics, and less chemistry.) I then noticed the similarity between lambda and Lambert, and (without doing any actual WP:OR) that they might be related. On the other hand, there are only so many letters, and after a while some do get reused. Gah4 ( talk) 21:50, 17 February 2022 (UTC)
I included the lambda in the history section. I do not believe that Beer used the symbol in the same way we use "absorption coefficient" today, but closer to what we would mean by the product "epsilon x length". DJDahm ( talk) 10:34, 15 May 2023 (UTC) DJDahm âÂ
I looked at the comments and gave it my best shot. I tried to include references in what I wrote, but did not look for them in the math section. A major facto is that Beer's law has come to mean much more than the relatively straight forward use in Chemical Spectroscopy. I tried to enlarge the scope rather than restrict the article to the tem in the title.
Sometime, someone should include illustrations. DJDahm ( talk) 14:21, 17 May 2023 (UTC)
Quite the contrary. Taken from Beer's paper: "Ist der hieraus sich ergebende SchwĂ€chungs - Coefficient λ, so hat er fĂŒr eine doppelte Dicke den Werth λ^2. Bei der doppelten Dicke wird aber ebenso viel concentrirte Lösung durchstrahlt, als bei der Dicke eines Decimeters und der VerdĂŒnnung 1/9." In other words, concentration Ă path length = const. Beenhereb4 ( talk) 18:06, 5 May 2024 (UTC)
![]() | This ![]() It is of interest to the following WikiProjects: | |||||||||||||||||
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"...relates the attenuation of light to the properties of the material through which one substance like light, neutrons or host rarefied gases is traveling"
Is light now a substance?
It's not clear what the defining characteristics are of the class "substance like light, neutrons or host rarefied gases". Would whey (traveling through cheesecloth) count?
So if you have neutrons passing through a material, light is attenuated? What light is affected?
I realize that it's difficult to explain highly technical subjects to fourth-graders, but it would make this highly important page MUCH more useful if was written clearly, instead of simply tossing keywords on the page, without bothering to ensure the sentences make sense. 12.193.238.99 ( talk) 23:08, 20 September 2014 (UTC)
Dr Bob, I'm not sure where you are from...but google beer lambert and mostly everyone in our World (Earth) uses A = Δ b c.
Dr Bob...the reason we introduce other variables is because not everyone is like dr bob and some of us use different variables. : )
Yes, but wouldn't it be better if we used standard IUPAC nomenclature "A = Δcl" instead?
Does this make sense: "If concentration c is expressed in moles per unit volume, α is a molar absorptivity usually given in units of mol cm-2?" Shouldn't it say in units of cm2 mol-1? Srnec 04:30, 16 February 2006 (UTC)
Am I the only one who feels the picture is unsuitable? The rhodamine is fluorescing - the light that is diminishing with greater pathlength is not the incident beam but light arising from the absorption of the incident beam. that's adding a whole new layer of confusion - could someone post a similar picture with a non-fluorescing material? Or a picture of a pane of glass from the from and side, showing how the increased pathlength leads to increased absorption resulting in the glass looking green from the side â Preceding unsigned comment added by 86.46.54.236 ( talk) 16:30, 6 July 2012 (UTC)
This picture should be indeed removed. The figure illustrates fluorescence and not absorption! Trelam ( talk) 19:48, 11 February 2015 (UTC)
I think the article should more explicity explain the relationship beween absorbance and transmittance, or point to an article that does cover this. It is sort of in the article already (Ii/Io), but that wouldn't be clear to the uninitiated. ike9898 17:43, 14 March 2006 (UTC)
I've added a simple derivation of the law, with an explanation of the problem at high concentrations. I've used the notation in the previous section, although I do not like it - for reasons that others have already mentioned. It seems we're married to the notation used in the figure, and this is unfortunate. ike9898 - I added a line defining transmittance after seeing your comment.
This is actually my first contribution, and my first attempt at LaTex. The fonts don't look quite right, and I would welcome anyone attempting to clean it up.
Axewiki 12:51, 13 September 2006 (UTC)
This looks a lot like the few other derivations I was able to find on the web.... neffk ( talk) 06:23, 21 November 2009 (UTC)
I left a nice clean derivation on this website in 2006, and came back now only to find it replaced by a messy cluttered derivation, wholly unsuitable for my students. Symbols are unnecessarily complex, difficult to read, and in at least one case, undefined. Rather discourages efforts to edit ... Axewiki ( talk) 03:19, 13 July 2015 (UTC)
Beer-Lambert law is a conection of Beer law and Lambert law, so in the very first line is untrue information. Both are now historical, but...
So if you have time to fix it, please do it. Probably it will need a minor changes in biographical articles about Beer and Labbert. -- 82.139.42.165 23:16, 25 September 2006 (UTC)
Precise references are needed to back up the history section, particularly with regards the role of Bouguer. Ga2re2t 17:00, 25 October 2007 (UTC)
I found the equation (4th equation from this article) to be confusing
I reasoned, since alpha has various sets of units (see paragraph below) so must k, yet the way k is derived in the article Extinction coefficient indicates that k has only one set of units, and if the equation above is correct alpha must have only one set of units, which comes back to my point that I am confused.
So I wanted to ask/plead that someone who knows whats going on, amend either the paragraph below quoted from the article or the equations, such that the whole thing is less confusing. Or at least so that the units for the equation are clear.
"The units of c and α depend on the way that the concentration of the absorber is being expressed. If the material is a liquid, it is usual to express the absorber concentration c as a mole fraction i.e. a dimensionless fraction. The units of α are thus reciprocal length (e.g. cmâ1). In the case of a gas, c may be expressed as a density (units of reciprocal length cubed, e.g. cmâ3), in which case α is an absorption cross-section and has units of length squared (e.g. cm2). If concentration c is expressed in moles per unit volume, α is a molar absorptivity (usually given the symbol Δ) in units of molâ1 cmâ2 or sometimes L molâ1 cmâ1." â Preceding unsigned comment added by 139.67.205.181 ( talk)
Something is wrong with the first section (2007-03-22). There's a missing ln(10) somewhere. This is obvious, since A is defined in terms of log10, but the rest of the constants are non-log quantities. I'm not sure where it goes, though. âThe preceding unsigned comment was added by 192.249.47.9 ( talk) 19:04, 22 March 2007 (UTC).
A user named "Anarotram" deleted a section of the derivation I composed and left the message "I deleted the last comment that appears entirely wrong. The requirement on the slab thickness dz is not involved in the integration step. I deleted the last comment that appears entirely wrong. The requirement on the slab thickness dz is not involved in the integration step.". There is no record of this user making any other edits to Wikipedia pages.
This comment does not explain what Anarotram believes is wrong. The integration is clearly over dz, so the comment is puzzling. Also, the sentence beginning with "The requirement ..." is fractured English, so I'm not even sure what it means.
The effects of error in this assumption is a basic spectroscopic phenomenon that I have students prove to themselves when they first start working with a spectrophotometer. The phenomenon is real, and has a very simple basis. If Anarotrim has another explanation it should be entered into the discussion before a widely accepted explanation is merely deleted. Axewiki 21:13, 18 August 2007 (UTC)
IUPAC recommends that Δ be called the molar (decadic) absorption coefficient. See
[1],
[2], and especially
[3].
â DIV (
128.250.204.118 08:20, 7 September 2007 (UTC))
I am under the impression that absorptivity should not redirect to this page.
Absorptivity, as it pertains to heat transfer and infrared radiation/optics, is a simple ratio of the irradiation absorbed over the total irradiation. Where, the total irradiation is the radiative flux incident to a surface, both from direction emmission and reflection from all other surfaces in a system. Additionally this unit is dimenssionless and is also given by the greek letter alpha.
The strict definition of absorptivity in infrared radiation is completely analagous to reflectivity and the emissivity.
Furthermore, several wikipedia pages reference and link to this page on absorptivity however they are obviously refering to the dimensionless absorptivity and not to the absorbance that this article discusses.
I could and probably will fix this inconsistency, by the end of the year hopefully, with the addition of a start up article on absorbtivity.
I would appreciate feed back on the discussion page or my talk page. The Lamb of God ( talk) 16:32, 17 June 2009 (UTC)
Absorptivity is only equal to the emissivity in an isothermal inclosure, that is, an object in thermal equillibrium. So, in regards to black bodies, the absorptivity is always equal to the emissivity and both have a value of 1.
This is given in Kirchoff's Law. And as you have probably discovered the absorptivity refered to in Kirchoff's Law and the emissivity articles link to this article.
I am working on expanding the Kirchoff's Law page also, (which is where the issue started in the first place.) So, in conjuction I will see what I can do.
In the mean time I do not know what absorptivity should link too???
I may simply create a 1 paragraph article in the short term and direct it there or follow your suggestion and do the 1 paragraph in emissivity. The Lamb of God ( talk) 14:47, 18 June 2009 (UTC)
Please use the terms Naperian and decadic to distinguish between natural and common logarithms. This is what IUPAC does. IUPAC generally tries to reconcile differing notations between different fields. I've personally never seen used in a decadic system. Also, Naperian vs decadic doesn't really have anything to do with the analyte's state of matter. The solid phase isn't even mentioned! Naperian and decadic definitions are just a matter of different fields having different traditions. 128.146.32.223 ( talk) 01:54, 2 September 2009 (UTC)
"Please use the terms Naperian and decadic to distinguish between natural and common logarithms." These two comments look like an example of absurdly preferring gobbldegook over plain language. If you mean common logs just say that, and the same for natural logs. There is nothing wrong with simply saying what you mean... âPreceding unsigned comment added by 82.32.49.157 ( talk) 11:13, 2 February 2011 (UTC)
This article is ridiculously verbose. There are way too many examples, at most one example is needed. In particular the "Chemical Analysis" and "BeerâLambert law in the atmosphere" sections could simply be deleted. The discussion about different units is unimportant to a general audience. (As a matter of fact, it can be highly confusing to specialists.)
I've tried googling for it (define: aborbance) and I've tried m-w.com--neither one defines it. If I search for aborbance, I find lots of references to it (over a 1000, iirc), but my guess they are all careless misspellings.
I was going to correct the spelling, but I have just a little bit of doubt. (If someone does correct it, search the page, I think there is more than one occurrence.)
Rhkramer ( talk) 11:40, 2 November 2010 (UTC)
I have edited the Prerequisites paragraph, presenting the 2 conditions which were originally stated under item (2) as separate requirement (now 2 & 3, the remainder being renumbered up to 6). I have no argument with these requirements. But, when they are stated explicitly, which is a good thing to do, it is clear that the illustration (which involves fluorescence) cannot be a good example of the law in action, since it transgresses condition (3) "no scattering" and also condition (6) "no influence on medium". For the sake of consistency, either a better illustration should be found, or the reasons for ignoring these transgressions (change in wavelength - the B-L law can be applied to the original green light only) should be given. Dr Andrew Smith âPreceding unsigned comment added by 82.32.49.157 ( talk) 11:07, 2 February 2011 (UTC)
I'm a third year pharmacy student, and I've done my first year of basic chemistry, and even I find it difficult to follow this page. I can't imagine how this looks to person with a non-science background. I of all people understand the need to explain things properly, but this page seriously needs to be simplified somehow. I've not seen anything resembling "A = Δ b c", nor do I think I have seen a mentione of Δ1%. Seriously, please do something about this Chairman Xi ( talk) 05:31, 10 March 2012 (UTC)
It is implicit in the law that shadowing must occur. This is because the incident intensity on the infinitesimally thin slab is dependent on the output intensity of the slab before. If no shadowing occurred, there would be no need to perform calculus and the entire slab would be considered as one. Putting this falsehood back in the article is lying to people. If you think better wording should be used, then try to word it better, but leave in the fact that the shadowing is required for the derivation of the law to hold true (which actually means the law breaks down at low concentration/pathlength/extinction coefficient) not high). Black.jeff ( talk) 20:30, 17 October 2013 (UTC)
References
I would like to point out that an editor of the French article has deleted the section on the atmosphere as "totalement faux" (totally false). When I asked for further explanation on the talk page, that editor and one other explained that the equation given does not apply to diffusive media such as the atmosphere. See discussion in French at fr:Discussion:Loi de Beer-Lambert#Suppression de section Loi de Beer-Lambert dans l'atmosphĂšre.
This raises the question of whether the section should be removed from the English article also. I don't know enough to judge whether the objections are valid. Perhaps those editors who are more expert in optical theory could read the French discussion and comment. Dirac66 ( talk) 00:59, 31 December 2016 (UTC)
I ended up watching some youtube videos explaining the law, which is a LOT simpler than the whole article there.
I have no problem with anyone explaining things in a complicated way per se, but wikipedia should also teach people; and from this point of view, the article is worded and structured in a WAY too complicated manner. Not everyone is a maths genius - the article was clearly written by physicists mostly. 2A02:8388:1603:CB00:3AD5:47FF:FE18:CC7F ( talk) 11:57, 10 December 2017 (UTC)
It occurred to me answering a question on Mass attenuation coefficient related to lambda, that lambda is commonly used for absorption coefficients (in the numerator of the exponent), though not in this article. (Maybe more in physics, and less chemistry.) I then noticed the similarity between lambda and Lambert, and (without doing any actual WP:OR) that they might be related. On the other hand, there are only so many letters, and after a while some do get reused. Gah4 ( talk) 21:50, 17 February 2022 (UTC)
I included the lambda in the history section. I do not believe that Beer used the symbol in the same way we use "absorption coefficient" today, but closer to what we would mean by the product "epsilon x length". DJDahm ( talk) 10:34, 15 May 2023 (UTC) DJDahm âÂ
I looked at the comments and gave it my best shot. I tried to include references in what I wrote, but did not look for them in the math section. A major facto is that Beer's law has come to mean much more than the relatively straight forward use in Chemical Spectroscopy. I tried to enlarge the scope rather than restrict the article to the tem in the title.
Sometime, someone should include illustrations. DJDahm ( talk) 14:21, 17 May 2023 (UTC)
Quite the contrary. Taken from Beer's paper: "Ist der hieraus sich ergebende SchwĂ€chungs - Coefficient λ, so hat er fĂŒr eine doppelte Dicke den Werth λ^2. Bei der doppelten Dicke wird aber ebenso viel concentrirte Lösung durchstrahlt, als bei der Dicke eines Decimeters und der VerdĂŒnnung 1/9." In other words, concentration Ă path length = const. Beenhereb4 ( talk) 18:06, 5 May 2024 (UTC)