Patent ID: 8760646

Claim:
A method for measuring size of microparticles, comprising: measuring, by a spectrometer, an extinction spectrum of a medium having microparticles dispersed therein; and calculating average size of the microparticles based on the measured extinction spectrum and the Mie scattering theory, by obtaining a maximum value and a minimum value of extinction efficiency from the extinction spectrum, and calculating the size of the microparticles by associating the maximum value and the minimum value of the extinction efficiency with the calculated extinction efficiency based on the Mie scattering theory, wherein the following equations are used by the spectrometer to calculate the extinction efficiency based on the Mie scattering theory Q EXT = 2 ( ka ) 2 ⁢ ∑ n = 1 ∞ ⁢ ( 2 ⁢ n + 1 ) ⁢ { Re ⁡ ( a n + b n ) } a n = m ⁢ ⁢ ψ n ⁡ ( mx ) ⁢ ψ n ′ ⁡ ( x ) - ψ n ⁡ ( x ) ⁢ ψ n ′ ⁡ ( mx ) m ⁢ ⁢ ψ n ⁡ ( mx ) ⁢ ξ n ′ ⁡ ( x ) - ξ n ⁡ ( x ) ⁢ ψ n ′ ⁡ ( mx ) b n = ψ n ⁡ ( mx ) ⁢ ψ n ′ ⁡ ( x ) - m ⁢ ⁢ ψ n ⁡ ( x ) ⁢ ψ n ′ ⁡ ( mx ) ψ n ⁡ ( mx ) ⁢ ξ n ′ ⁡ ( x ) - m ⁢ ⁢ ξ n ⁡ ( x ) ⁢ ψ n ′ ⁡ ( mx ) , ⁢ ψ n ⁡ ( x ) = x ⁢ ⁢ j n ⁡ ( x ) , ⁢ ξ n ⁡ ( x ) = x ⁢ ⁢ h n ( 1 ) ⁡ ( x ) x = ka = 2 ⁢ ⁢ π ⁢ ⁢ a λ , m = N p N h = RI ⁢ ⁢ ⁢ of ⁢ ⁢ the ⁢ ⁢ particles RI ⁢ ⁢ of ⁢ ⁢ the ⁢ ⁢ host ⁢ ⁢ matrix wherein an and bn are scattering coefficients, is a wavelength, k is a wave vector, a is the radius of a microparticle, m is a ratio of the refractive indices of the microparticles and surrounding medium, and j n (x) and h (1) n (x) represent the Riccati-Bessel function and the Riccati-Hankel function, respectively, RI represents refractive index, and x represents a size parameter for (n, k) data.