  Approximation of the previously estimated excess specific heat
C^{excess}/T^{5} of two fluoropolymers, PTFE and PCTFE, is presented using
Orthonormal Polynomial Expansion Method (OPEM). The new type of weighting
functions in OPEM involves the experimental errors in every point of the
studied thermal characteristic. The investigated temperature dependence of the
function C^{excess}/T^{5} is described in the whole temperature ranges 0.4\div8
K and 2.5\div7 K respectively for PTFE and PCTFE as well as in two subintervals
(0.4\div2) K, (2.5\div8) K for PTFE. Numerical results of the deviations
between the given C^{excess}/T^{5} data and their approximating values are
given. The usual polynomial coefficients obtained by orthonormal ones in our
OPEM approach and the calculated in every point absolute, relative and specific
sensitivities of the studied thermal characteristic are proposed too. The
approximation parameters of this type thermal characteristic are shown in
Figures and Tables.
