Comparison and Evaluation of Gas Reference Temperature Measurement Resonance Frequency Calculation Models

It aims to provide a unified experimental benchmark for four representative models: the rational function linear approximation method, the nonlinear rational function method, the real-domain Lorentz method, and the complex-domain Lorentz method. The dataset includes complete raw sweep-frequency data of complex radiation transmission parameters (S₂₁) measured over the temperature range of 10 K to 40 K, along with the fitted parameters, resonant frequencies, and half-width corrected resonant frequencies obtained from each model.Experimental data were acquired using a primary thermometry experimental platform.

A vector network analyzer performed frequency sweeps on a microwave resonator under vacuum conditions, recording complex transmission parameters at 144 frequency points per sweep. The same set of experimental data was then processed using the four calculation models to extract resonant frequencies. The dataset comprehensively documents the fitted parameters for each model (including numerator/denominator polynomial coefficients, background polynomial coefficients, Lorentz amplitudes, bandwidths, etc.), fitting residual distributions, iterative convergence processes, and resonant frequency uncertainty evaluation results.This dataset provides robust experimental evidence for validating the accuracy and precision of different fitting algorithms, analyzing the impact of model selection on resonant frequency extraction, and optimizing data processing strategies for cryogenic gas-based primary thermometry.