where, R = reflectance; k = absorption coefficient; s = scattering coefficient; c = concentration of the absorbing species; A = absorbance.

It gives a correlation between the reflectance and the concentrations of absorbing species in weak absorbing samples, something like the Lambert-Beer law for absorbance.

The Kubelka-Munk function was develop to analyse paint coated surfaces and therefore is expected that the analyzed surface is totally plane and with infinitesimal thickness. One limitation of the technique is its use in samples with different particle size were light scattering is high.

where, R = reflectance; k = absorption coefficient; s = scattering coefficient; c = concentration of the absorbing species; A = absorbance.

It gives a correlation between the reflectance and the concentrations of absorbing species in weak absorbing samples, something like the Lambert-Beer law for absorbance.

The Kubelka-Munk function was develop to analyse paint coated surfaces and therefore is expected that the analyzed surface is totally plane and with infinitesimal thickness. One limitation of the technique is its use in samples with different particle size were light scattering is high.

Mathias
One question to you: you say the K-B is used for weaky absorbing materials but it is also used in printing with black ink on paper whihc is a strongly absorbing medium

We used diffuse reflectance spectroscopy to differentiate between water and ice on different roads (see attached patent). Proof of principle was performed together with the Porsche Company in the Alpes. Within milliseconds also the thickness of ice and water on the street was measured during driving. Of course corrections for different surface roughness and reflectivities were performed.

Ata I just noticed:
You do not specify your question you only ask about "the" problems with the K-B approach. What is YOUR problem

Jan 10, 2013

Tibor Illés · Budapest University of Technology and Economics

Altough, I do not know what Ata might willing to ask exactly, but I do know about several computational problems related to two-constant Kubelka-Munk theory. Most of these computational problems are related to calibration procedures (i.e. related system of linear equations derived from two constant KM-theory). The main issues, up to my best knowledge, are the ill-conditionedness of these equations especially for low wavelength that may cause problems when the two constant KM-theory is applied for color matching problems.

I have an old operations research paper not really recognized by the color research community. If you want to read the paper please go to http://www.sciencedirect.com/science/article/pii/0377221794900647
If anyone is interested on more details related to computational problems arising during the calibration procedure please contact me.

I don't know what is the problem with his samples, but, a problem to me is for exemple: in the end moment to determination of band gap I should plot [F(R∞)hv]2 against hv and take the zero for extrapolation of the linear portion of the curve. But, this "2" is relative a nature of optical transition. If I don't have this information in the literature, what should I do?

I have a question though about the KM function. If the k in KM function is the absorption coefficient, is this the same as the absorption coefficient (alpha) used in Tauc plot method for attaining the band gap? Where we plot (ahv)^p vs hv to obtain the intersect

## Popular Answers

Mathias Strauss· University of CampinasF (R) = (1–R)²/2R = k/s = Ac/s

where, R = reflectance; k = absorption coefficient; s = scattering coefficient; c = concentration of the absorbing species; A = absorbance.

It gives a correlation between the reflectance and the concentrations of absorbing species in weak absorbing samples, something like the Lambert-Beer law for absorbance.

The Kubelka-Munk function was develop to analyse paint coated surfaces and therefore is expected that the analyzed surface is totally plane and with infinitesimal thickness. One limitation of the technique is its use in samples with different particle size were light scattering is high.

You can get some information is the text below:

Diffuse Reflectance Spectroscopy

JOSÉ TORRENT and VIDAL BARRÓN

http://www.uco.es/organiza/departamentos/decraf/pdf-edaf/DRS08.pdf

## All Answers (8)

Mathias Strauss· University of CampinasF (R) = (1–R)²/2R = k/s = Ac/s

where, R = reflectance; k = absorption coefficient; s = scattering coefficient; c = concentration of the absorbing species; A = absorbance.

It gives a correlation between the reflectance and the concentrations of absorbing species in weak absorbing samples, something like the Lambert-Beer law for absorbance.

The Kubelka-Munk function was develop to analyse paint coated surfaces and therefore is expected that the analyzed surface is totally plane and with infinitesimal thickness. One limitation of the technique is its use in samples with different particle size were light scattering is high.

You can get some information is the text below:

Diffuse Reflectance Spectroscopy

JOSÉ TORRENT and VIDAL BARRÓN

http://www.uco.es/organiza/departamentos/decraf/pdf-edaf/DRS08.pdf

Harry ten Brink· Energy Research Centre of the NetherlandsOne question to you: you say the K-B is used for weaky absorbing materials but it is also used in printing with black ink on paper whihc is a strongly absorbing medium

Karl Cammann· University of MünsterHarry ten Brink· Energy Research Centre of the NetherlandsYou do not specify your question you only ask about "the" problems with the K-B approach. What is YOUR problem

Tibor Illés· Budapest University of Technology and EconomicsI have an old operations research paper not really recognized by the color research community. If you want to read the paper please go to

http://www.sciencedirect.com/science/article/pii/0377221794900647

If anyone is interested on more details related to computational problems arising during the calibration procedure please contact me.

Sayonara Eliziario· Universidade Federal de São CarlosTing Qiao Leow· Universiti Teknologi MalaysiaI have a question though about the KM function. If the k in KM function is the absorption coefficient, is this the same as the absorption coefficient (alpha) used in Tauc plot method for attaining the band gap? Where we plot (ahv)^p vs hv to obtain the intersect

Nahum Gat· OptoKnowledge SystemsHow do the k and s in the Kubelka-Munk function relate to the index of refraction -- specifically the real and imaginary parts (k,n) of the index?

Can you help by adding an answer?