Abstract：Due to the complexity of the circuit architecture, high integration and diversity of nonlinear error sources in ADC based resistance thermometry readout, the effect of the existing nonlinear error correction method is not significant. Aiming at these shortcomings, a novel nonlinear error correction method based on the error sources analysis was proposed for ADC based readout. In the method, the influences of the common-mode rejection ratio, the mismatch of the forward and reverse exciting current were analyzed in mathematically. With the resistance bridge calibrator, these two errors were estimated and corrected, Then the residuals were fitted by the linear polynomial. To verify the effect of the proposed correction method, an ADC-based resistance thermometry readout and a resistance bridge calibrators were developed in the study. The experimental results showed that after the correction of the proposed method, the maximum nonlinear error of the readout is -1.77×10-5, while with the correction of the traditional method, the maximum nonlinear error is -3.57×10-5. The circuit schematics and measurement procedures of the ADC based thermometry readout were released, this is helpful for the countrys the ADC based high-precision resistance thermometry readout development and commercialized.
［1］Nicholas J V, White D R. Traceable Temperatures an introduction to temperature measurement and calibration ［M］. 2nd ed. West Sussex:John Wiley & Sons Ltd,2001.
［2］王云静, 王玉田, 曲正伟. 数字微差补偿器及其在电流比较仪电桥中的应用［J］. 计量学报, 2015, 36(5): 530-534.
Wang Y J, Wang Y T, Qu Z W. A Digital Compensator and Its Application in Current-comparator Bridge［J］. Acta Metrologica Sinica, 2015, 36(5): 530-534.
［3］Rudtsch S, Ramm G, Heyer D, et al. Comparison of test and calibration methods for resistance ratio bridges ［C］// Proc TEMPMEKO 2004. Dubrovnik,2004:773–780.
［4］White D R, Jones K, Williams J M, et al. A simple resistance network for calibration resistance bridges ［J］. IEEE Transactions on Instrumentation and Measurement, 1997, 46(5): 1068-1074.
［5］Pearce J V, Gray J, Veltcheva R I. Characterisation of a selection of AC and DC Resistance Bridge for standard platinum resistance thermometry ［J］. International Journal of Thermophysics, 2016, 37(11): 109.
［6］Chojnacky M, Kosior J, Chaves-Santacruz L, et al. Performance assessments of thermometer resistance bridges ［R］. NIST Thermodynamic Metrology Group, 2002.
［7］方信昀, 孙建平, 曾凡超, 等. 高精密测温电桥的标定与评估［J］. 计量学报, 2016, 37(3): 265-270.
Fang X Y, Sun J P, Zeng F C, et al. Calibration and Evaluation on High Precision Thermometry Bridge. Acta Metrologica Sinica, 2016, 37(3): 265-270.
［8］Walker R. Automatic linearity calibration in a resistance thermometry bridge ［J］. International Journal of Thermophysics, 2011, 32(1-2): 215-223.
［9］Massa E, Mana G. An automated resistor network to inspect the linearity of resistance-thermometry measurements ［J］. Measurement Science and Technology, 2013, 24(10): 107001.
［10］Chen L, Ma D B, Sun J P. A convenient linearity calibration method for precision ratio bridges ［C］//2014 IEEE 9th Conference on Industrial Electronics and Application. Beijing, 2014.
［11］Taylor H R, Navarro H A. A microcomputer-based instrument for applications in platinum resistance thermometry ［J］. J Phys E: Sci Instrum, 1983, 16(11): 1100-1104.
［12］刘岩, 乔玉娥, 丁晨, 等. 10GΩ在片高值电阻溯源实验［J］. 计量学报, 2018, 39(4): 545-548.
Liu Y, Qiao Y E, Ding C, Liang F G. Traceability Experiments on 10GΩ On-wafer High Resistance. Acta Metrologica Sinica, 2018, 39(4): 545-548.
［13］Podgornik T, Batagelj V, Winkler G, et al. Evaluation of a modified ADC-based thermometry bridge ［J］. International Journal of Thermophysics, 2011, 32(11-12): 2409-2419.
［14］Walker R W. Resistance bridge architecture and method:US8253427［P］. 2012-08-28.
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