Theiss Research

Purpose: the Purpose of the Proposed Research Is to Improve Temperature Realization Cells That Are Used to Calibrate the Standard Platinum Resistance Thermometers. Activities to Be Performed: the Main Goals of This Project Are to Improve the Realization, Maintenance, and Dissemination of the ITS-90, and to Promote the Access to the Technical Information Relative to the Updated Best Practices for Realizing the Scale. This Project Can Be Subdivided in Four Topics, as Follows:a) ITS-90 Fixed-points Cells: Investigation of Traditional ITS-90 Fixed-point Cells, Realization Techniques, Sources of Measurement Errors, Such as Immersion, Heat Flux and Self-heating, and the Causes of Cell Failure; Investigation of the Use of Sealed Cells for SPRT and Thermocouple Calibrations.b) Novel Fixed-points Cells: Investigation of Novel Fixed Points, Such as the Triple Points of SF6 and CO2, as Alternatives to Reduce the Dependence on the Mercury Triple Point in the ITS-90; Determination of Their Realization Temperatures; Investigation of the Impact of Calibrations at These Points Instead of the HG Point on the Interpolated Temperatures.c) Improvements in the Scale: Investigation of the Non-uniqueness and Sub-range Inconsistencies in the ITS-90 Interpolation Functions; Investigate Alternative Interpolation Functions to the Currently Adopted in the Scale, If Necessary.d) Dissemination of Technical Information to the Public: Publication of the Project?s Achievements in Peer-reviewed Journals; Presentations in Technical Conferences; Developing Material and Leading Training Courses to the Temperature Community in the Usa and Abroad.expected Outcomes: the Expected Outcomes Include Characterizing Fixed-point Cells, by Measuring Their Phase Transition Temperatures, and Assessing Parameters Such as Plateau Length, Slope, Immersion Profile and Thermal Anchorage to the Realization Apparatus and External Environment; Characterizing Sprts in the Fixed-point Cells That Cover the ITS-90 Range, as Well as in the Novel Fixed-points Cells, by Measuring Their Electrical Resistances and Their Deviations With Relation to the Reference Values, and by Assessing Other Parameters Such as Self-heating and Heat Flux; Analysis and Consolidation of Experimental Data, Including the Calculation of the Measurement Uncertainties and Interpolation Functions; and Preparation of Scientific Articles for Publication in Peer-reviewed Journals, Such as the International Journal of Thermophysics or Metrologia.intended Beneficiaries: by Democratizing the Realization of the ITS-90 Scale Through New Cell Development and Technology (and Replacing the Toxic Mercury Cell), Companies Will Be Able to Perform ITS-90 Scale Realizations On-site Whether That Be in a Research Laboratory, Calibration Laboratory, or on the Manufacturing Floor.subrecipient Activities: the Recipient Does Not Intend to Subaward Funds.