Modern Gas-Based Temperature and Pressure Measurements

and 273.16 K and Scale approximations using sealed fixed points.- Realization of the ITS-90 in the Laboratories .- Approximating the ITS-90.- Gaseous Standard Reference Materials and the sealed cells.- Summary of triple-point sealed-cell design criteria.- Summary of sealed-cell fabrication techniques.- Summary of the sealed-cell measurement procedures by step-melting.- Gas thermometry between 0.5 K and 273.16 K.- Constant volume gas thermometry.- Influence of physical parameters.- Virial coefficient.- Amount of "active" substance.- Gas purity.- Influence of technical parameters.- The gas bulb.- Pressure measuring line.- Filling molar density.- Gas thermometer with built-in pressure measuring device.- Use of a CVGT with a differential cryogenic pressure transducer .- Use of a CVGT with an absolute pressure transducer.- The bulb volume of the gas thermometer.- Interpolating constant-volume gas thermometers.- ICVGT types with stipulation of the virial function.- Three-fixed point ICVGTs.- Two-fixed point ICVGTs.- Four-fixed point ICVGTs.- ICVGT types without stipulations.- Three-fixed point ICVGTs.- Two-fixed point ICVGTs.- Four-fixed point ICVGTs.- Gas thermometer realization.- CVGTs with reference at temperatures lower than 273.16 K.- Measuring bulb.- Pressure capillary.- Pressure measuring system.- Modern realizations.- CVGTs with reference temperature at 273.16 K.- CVGTs using a cryogenic pressure-measuring gauge.- Realizations of interpolating gas thermometers.- Gas thermometry in the ITS-90, and future development.- Dielectric-constant, refractive-index, and acoustic gas thermometers.- Dielectric-constant gas thermometer.- Refractive index gas thermometer.- Acoustic thermometer.- Summary of design criteria for an absolute CVGT in the low temperature range .- Summary of differences and simplifications in design criteria of an ICVGT.- Summary of the measurements procedures for an absolute CVGT in the low temperature range.- Summary of differences and simplifications in measurements procedures for an ICVGT.- Vapor-pressure thermometry.- Influence of physical parameters.- Purity of the substance.- Effect of impurities.- Scale errors due to impurities.- Isotopic- and isomeric-composition errors.- Effect of magnetic fields.- Amount of substance .- Influence of technical parameters.- Thermometer with gauge for pressure measurement at room temperature.- Thermometer volume.- Pressure measurement.- Pressure corrections.- Thermal problems.- Use of sealed cells for vapor pressure measurements.- Thermometer with gauge for pressure measurement at low temperature.- Liquid-vapor versus solid-vapor equilibria.- Realization of vapor-pressure temperature scales.- Equations for vapor pressure.- Helium vapor pressure.- 3He Scale (formerly T62).- 4He Scale (formerly T58).- ITS-90 between 0.65 K and 5.0 K.- Gas thermometry versus vapor-pressure thermometry below 5 K.- Summary of design criteria for vapor-pressure thermometers.- Summary of fabrication techniques for vapor-pressure thermometers.- Summary of measurement procedures with vapor-pressure thermometers.- Thermometry based on the melting line of 3He.- The 3He melting-line thermometer.- Melting line experiment below Tmin.- Melting line experiment above Tmin.- Pressure and temperature measurement.- The PLTS-2000 Scale.- Cryostats for thermometry and gas-based temperature control.- Cryostats.- Refrigerator-based cryostats.- Closed-cycle types (0.3 K to 300 K).- Refrigerated-bath thermostats (200 K to 300 K).- Liquid-refrigerant cryostats.- Bath cryostats.- Flow cryostats.- Temperature control in thermometry and gas-based temperature controls.- Control of the cryogen bath temperature.- Vapor-flow technique.- Passive thermostats.- Self-regulated passive shields.- Gas-filled heat switches.- Gas-type heat switches.- Thermosyphon- and condensation-type heat switches.- Strategy for cryostat selection.- Further Readings.- Bibliography Part I.- PART II Pressure measurements (102 to 108) Pa .- List of Symbols.- Introduction.- Primary standards for pressure measurements.- Liquid-column manometers for pressure measurements.- Operating principles and general precautions for absolute pressure measurements below 0.3 MPa .- Basic apparatus in metrological laboratories Different methods for height measurements..- White-light interferometer manometers.- Laser interferometer manometers.- Capacitance/gauge-block manometer.- Capacitance/interferometer manometers.- Ultrasonic manometers.- Calculations applicable with mercury-column manometers Pressure measurement uncertainty .- Mercury density.- Acceleration due to gravity.- Aerostatic head.- Reference pressure, p0.- Uncertainty of pressure measurements by liquid-column manometers.- Liquid columns for different applications.- Gas-operated piston gauges.- Basic description.- Absolute pressure measurements up to 5 MPa .- Mass.- Local acceleration due to gravity.- The effective area.- Elastic distortion coefficient .- Linear thermal expansion coefficients .- Temperature of the piston-cylinder assembly .- The reference pressure, p0.- Aerostatic-head corrections.- Gauge pressure measurements up to 100 MPa .- Air density.- Pressure distortion coefficients Controlled-clearance and similarity methods .- Uncertainty of absolute and gauge pressure measurements with piston gauges.- Differential gas pressure measurements.- Results of comparison measurements in gas media.- Comparisons of liquid-column manometers and piston gauges.- What future for primary pressure standards ? .- Summary of typical uncertainty levels for liquid-column manometers and piston gauges.- Pressure transducers for gaseous media.- Introduction.- Transfer standards for absolute pressure measurements below 120 kPa.- Transfer standards for atmospheric pressure measurements.- Transfer standards for gas pressure measurements from 100 Pa to 10 kPa.- Transfer standards for pressure measurements up to 100 MPa.- Transducers used for differential pressure measurements and as null detectors.- Differential pressure transducers for high line pressures.- Differential pressure transducers used as null detectors.- Transducers for pressure measurements in cryogenic environments.- Strain-gauge pressure transducers for cryogenic applications.- Resonant- and capacitance-type pressure transducers for cryogenic applications.- Glossary.- Terms used in the metrological characterization of a pressure transducer.- Typical procedure for the static calibration of a pressure transducer in gaseous media.- Gas based pressure fixed points.- Introduction.- The pressure scale from 102 to 108 Pa based on fixed points.- Triple points.- Other pressure fixed-points.- Experiences in the use of fixed points as pressure transfer standards.- Summary of possible fixed points to be used as transfer standards for gas pressure measurements from 100 Pa to approximately 100 MPa.- The thermomolecular pressure difference effect.- Introduction.- The calculation of the thermomolecular pressure difference.- Experimental measurements of the thermomolecular pressure difference.- General considerations on experimental measurements and theoretical calculations of the thermomolecular pressure difference.- Further Readings.- Bibliography Part II.- The Mutual Recognition Arrangement and its implementations.- Introduction.- The key comparisons.- The calibration and measurement capabilities.- The BIPM KCDB.- Appendix 1 - The international Temperature Scale of 1990.- Annotated text of the parts of the definition below 273.16 K.- Notes on scale differences.- The Scale PLTS-2000.- Appendix 2 - List of temperature and pressure fixed points.- Appendix 3 - Reference data on gases.- Appendix 4 - Vapor pressures.- Appendix 5 - Reference data for liquid-column manometers.- Appendix 6 - Reference data for piston gauges.- Appendix 7 - The text of the Mutual Recognition Arrangement.-