Patent ID: 8498837

Claim:
A method for paramagnetism-based remote temperature measurement of a measured object using magnetic nanoparticles, comprising: (1) positioning a sample of said magnetic nanoparticles at an area of said measured object; (2) applying n times of different excited magnetic fields on said area, where n≧2; (3) collecting magnetization of said sample under said different excited magnetic fields, and detecting magnetic susceptibility of said sample under said different excited magnetic fields according to said magnetization; (4) constructing equations between said magnetic susceptibility and said different excited magnetic fields 1 χ i = H i NML ⁡ ( MH i kT ) , ⁢ i = 1 , 2 ⁢ ⁢ … ⁢ ⁢ n , wherein; χ i is said magnetic susceptibility; H i is said different excited magnetic fields; reciprocal of the Langevin's function L ⁡ ( MH i kT ) ⁢ : ⁢ ⁢ 1 L ⁡ ( α ) = ∑ j = 0 J ⁢ c 2 ⁢ j - 1 ⁢ α 2 ⁢ j - 1 ; α = MH i kT ; c 2j-1 is a polynomial coefficient; J+1 is a predetermined polynomial expansion term; N is concentration of said sample; M is atomic magnetic moment of said sample; k is a Boltzmann's constant; and T is temperature of said measured object; 5) solving said equations, using a processor, to obtain said temperature T, wherein J=1, and step (5) comprises: using a linear equation 1 χ i = 3 ⁢ x + 1 5 ⁢ H i 2 ⁢ y to perform curve fitting on a sequence point ( H i 2 , 1 χ i ) ; and calculating said temperature according to an intercept 3x and a slope 1 5 ⁢ y of a straight line obtained by said curve fitting: T = M k ⁢ ⁢ x y .