Search results
Results From The WOW.Com Content Network
The SI unit of molar absorption coefficient is the square metre per mole (m 2 /mol), but in practice, quantities are usually expressed in terms of M −1 ⋅cm −1 or L⋅mol −1 ⋅cm −1 (the latter two units are both equal to 0.1 m 2 /mol).
absorption coefficient is essentially (but not quite always) synonymous with attenuation coefficient; see attenuation coefficient for details; molar absorption coefficient or molar extinction coefficient , also called molar absorptivity , is the attenuation coefficient divided by molarity (and usually multiplied by ln(10), i.e., decadic); see ...
Variable pathlength absorption spectroscopy uses a determined slope to calculate concentration. As stated above this is a product of the molar absorptivity and the concentration. Since the actual absorbance value is taken at many data points at equal intervals, background subtraction is generally unnecessary.
Extinction coefficient refers to several different measures of the absorption of light in a medium: Attenuation coefficient, sometimes called "extinction coefficient" in meteorology or climatology Mass extinction coefficient, how strongly a substance absorbs light at a given wavelength, per mass density
The magnitude of the constant φ may be higher than the value of the molar extinction coefficient, ε, for a species. When this is so, the detection limit for that species will be lower. At high solute concentrations, fluorescence intensity becomes non-linear with respect to concentration due to self-absorption of the scattered radiation.
To convert heat values to joules per mole values, multiply by 44.095 g/mol. To convert densities to moles per liter, multiply by 22.678 cm 3 mol/(L·g). Data obtained from CRC Handbook of Chemistry and Physics , 44th ed. pages 2560–2561, except for critical temperature line (31.1 °C) and temperatures −30 °C and below, which are taken from ...
In general, an index of refraction is a complex number with both a real and imaginary part, where the latter indicates the strength of absorption loss at a particular wavelength—thus, the imaginary part is sometimes called the extinction coefficient.
Note that T = 0 for the glass substrate in the DUV, indicating absorption in this range of the spectrum. It is found that the value of k(λ) in the deep UV wavelength range is of the order of k = 3 × 10 −4, and this small non-zero value is consistent with T = 0 in the deep UV.