Abstract
Platinum resistance thermometers (PRTs) are calibrated at the highest level in fixed points, as specified in the International Temperature Scale of 1990 (ITS-90). However, in order to reduce cost and time, platinum resistance thermometers can also be calibrated by comparison. In the temperature range from −100 °C to 300 °C, it is possible to achieve uncertainties as small as 5 mK. A PRT is calibrated by comparison by comparing its resistance reading with the temperature reading of a reference thermometer, placed at the same temperature inside the temperature-controlled calibration medium. The reference thermometer is commonly also a resistance thermometer, so the intrinsic measurement problem is the simultaneous measurement of two resistances. Four methods that perform this measurement are presented in this article. A special emphasis is given to the measurement with slow bridges. Slow bridges are not able to produce a stable resistance reading within 20 s after the connection of the PRT, so they are often considered to be unsuitable for calibration by comparison of PRTs. To overcome this problem, a special method that directly measures the ratio between the reference PRT and PRT under calibration is presented and analyzed. The analysis and measurement results proved that this method and consequently the slow resistance bridges are capable of performing calibration by comparison of PRTs at least at the same level as the conventional methods.
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References
Preston-Thomas H.: Metrologia 27, 3 (1990)
Nicholas J.V., White D.R.: Traceable Temperatures, pp. 153–198. Wiley, Chichester (1994)
J. Dubbeldam, M. de Groot, Uncertainty Budget for Calibrations of Industrial PRTs, presented at the EUROMET Workshop (Berlin, Germany, 2001)
J. Bojkovski, V. Batagelj, J. Drnovšek, V. žužek, IMEKO XIX World Congress (Lisbon, Portugal, 2009), pp. 1581–1584
T. Weckström, in Proceedings of TEMPMEKO 2004, 9th International Symposium on Temperature and Thermal Measurements in Industry and Science, ed. by D. Zvizdić, L.G. Bermanec, T. Veliki, T. Stašić (FSB/LPM, Zagreb, Croatia, 2004), pp. 813–816
Batagelj V., Bojkovski J., Drnovšek J.: IET Sci. Meas. Sci. Technol. 2, 100 (2008)
Batagelj V., Bojkovski J., Drnovšek J.: Meas. Sci. Technol. 14, 2151 (2003)
V. Batagelj, J. Bojkovski, J. Drnovšek, I. Pušnik, in Temperature: Its Measurement and Control in Science and Industry, vol. 7, ed. by D.C. Ripple (AIP, Melville, New York, 2003), pp. 315–320
D. Brown, Resistance Measurements Systems w/Sub PPM Accuracy—1uΩ to1GΩ, Technical paper, http://www.mintl.com/media/pdfs/1uohm_1Gohm_insert.pdf
Begeš G., Drnovšek J., Pendrill L.R.: Accredit. Qual. Assur. 15, 147 (2010)
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Batagelj, V., Bojkovski, J. Calibration by Comparison of Platinum Resistance Thermometers Using Slow Resistance Bridges. Int J Thermophys 32, 1409–1417 (2011). https://doi.org/10.1007/s10765-011-1010-2
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DOI: https://doi.org/10.1007/s10765-011-1010-2