techniques for approximating the international temperature ... - BIPM
techniques for approximating the international temperature ... - BIPM techniques for approximating the international temperature ... - BIPM
12 Fig. 2.2: Cryostat for calibration of resistance thermometers: D, outline of helium dewar; HE, liquid helium reservoir; PT, pumping tube; SS, stainless-steel vacuum can; I, indium seal; R, radiation shield; A, one of four access tubes for wires; B, binding post for wires; T, one of four support tubes; V, vacuum; S, temperature control sensor; H, heater; C 1, copper thermometer block; C2, copper isothermal shield; P, platinum thermometer; G, germanium thermometer [after Rusby et al. (1972)].
13 Fig. 2.3: Flow cryostat, shown with a vapour pressure bulb fitted: 1, pressure tube with radiation traps; 9, bulb with thermometers; 15, 24, vacuum space pumped through; 8, outer shield, nitrogen cooled through inlet 13 and coil 7; 20, inner shield, helium cooled through syphon 14 and coils 12 and 21; 23, isothermal shield, with internal independent vacuum 22; 16, thermometers : for temperature regulation of the shield. [Blanke and Thomas (1979)]. The sealed-cell cryostat of Ancsin and Phillips (1984) can also be used as a comparator over the temperature range 84 K to 400 °C (see Sec. 3.1.4). In any of these systems, it is important that the thermometers be in good thermal contact with the block, as through the use of a vacuum grease. It is also important to prevent heat exchange between the thermometer and room temperature via the connecting leads; for this reason the thermometer leads, and an appropriate length [Hust (1970); Fellmuth and Seifert (1988)] of the connecting wires must be put in good thermal contact with the measuring block or with a body maintained at block temperature. However, this
- Page 1 and 2: BUREAU INTERNATIONAL DES POIDS ET M
- Page 3 and 4: TECHNIQUES FOR APPROXIMATING THE IN
- Page 5 and 6: iv W(100 °C) = 1.385 (exact value
- Page 7 and 8: Centre for Quantum Metrology Nation
- Page 9 and 10: 2. Type J viii a) temperature range
- Page 11 and 12: c) temperature range from 1664.5 °
- Page 13 and 14: xii
- Page 15 and 16: xiv Acknowledgments This monograph
- Page 17 and 18: xvi 3.3.2 Melting Points of Gold (1
- Page 19 and 20: xviii 11.3 Thermal Contact 111 11.4
- Page 21 and 22: 1 1. Introduction The Comité Consu
- Page 23 and 24: 3 thermometers except in special ex
- Page 25 and 26: 5 The accuracies with which tempera
- Page 27 and 28: Table 1.1: Summary of Some Properti
- Page 29 and 30: PART 1: TECHNIQUES AND THERMOMETERS
- Page 31: 11 Fig. 2.1: One form of apparatus
- Page 35 and 36: 15 Fig. 2.4: Stirred liquid bath fo
- Page 37 and 38: 17 contained within a cylindrical c
- Page 39 and 40: 19 Fig. 2.5: Schematic drawing of a
- Page 41 and 42: 21 device SRM 767 [Schooley et al.
- Page 43 and 44: 23 Table 3.1 : Current Best Estimat
- Page 45: 25 The widely-used, but not very re
- Page 48 and 49: 28 fraction of sample melted) can g
- Page 50 and 51: 30 Fig. 3.2a: Apparatus for the cal
- Page 52 and 53: 32 Fig. 3.3: Sealed cell for realiz
- Page 54 and 55: 34 Final readings of the thermomete
- Page 56 and 57: 36 temperatures differ (usually) sy
- Page 58 and 59: 38 Fig. 3.4: Cross sectional drawin
- Page 60 and 61: 40 Fig. 3.5: Miniature graphite bla
- Page 62 and 63: 42 4. Germanium Resistance Thermome
- Page 64 and 65: 44 Fig. 4.3: Example of the Π-type
- Page 66 and 67: 46 Fig. 4.4: Differences between dc
- Page 68 and 69: 48 - conversely, p-doped thermomete
- Page 70 and 71: 50 Fig. 4.6: Effect of a radio-freq
- Page 72 and 73: 52 that it will not be subject to m
- Page 74 and 75: ln R n = ∑ i= 0 54 ⎛ ln T - P
- Page 76 and 77: 56 Fig. 5.1: Resistance (Ω) and s
- Page 78 and 79: 58 thermometer wires) caused a more
- Page 80 and 81: 60 6. Vapour Pressure Thermometry*
12<br />
Fig. 2.2: Cryostat <strong>for</strong> calibration of resistance <strong>the</strong>rmometers: D, outline of helium dewar; HE,<br />
liquid helium reservoir; PT, pumping tube; SS, stainless-steel vacuum can; I,<br />
indium seal; R, radiation shield; A, one of four access tubes <strong>for</strong> wires; B, binding<br />
post <strong>for</strong> wires; T, one of four support tubes; V, vacuum; S, <strong>temperature</strong> control<br />
sensor; H, heater; C 1, copper <strong>the</strong>rmometer block; C2, copper iso<strong>the</strong>rmal shield; P,<br />
platinum <strong>the</strong>rmometer; G, germanium <strong>the</strong>rmometer [after Rusby et al. (1972)].
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