LXXIX.The reduction of platinum resistance thermometers to the international temperature scale

1932 ◽  
Vol 14 (93) ◽  
pp. 729-742
Author(s):  
G.S. Callendar
Keyword(s):  
Temperature Scale ◽  
Platinum Resistance ◽  
International Temperature Scale ◽  
International Temperature ◽  
Platinum Resistance Thermometers ◽  
Resistance Thermometers

The freezing point of zinc as a primary point of the International Temperature Scale

1958 ◽  
Vol 247 (1249) ◽  
pp. 214-224 ◽  
Keyword(s):  
Temperature Scale ◽  
Freezing Point ◽  
Platinum Resistance ◽  
International Temperature Scale ◽  
International Temperature ◽  
Platinum Resistance Thermometers ◽  
Resistance Thermometers ◽  
Accuracy Of Measurement ◽  
Definition Of ◽  
Freezing Point Of Zinc

The technique is described of achieving the highest accuracy of measurement with platinum-resistance thermometers at the freezing point of zinc and the boiling point of sulphur. The two points are compared in a series of measurements and it is found that the zinc point is some three or four times more reproducible than the sulphur point. It is concluded that the substitution of the zinc point for the sulphur point as a primary fixed point of the International Temperature Scale would lead to a greater precision in the definition of the scale. The value of the freezing point of zinc is found to be 419∙5055 ± 0∙002°C.

THE CALIBRATION OF PLATINUM RESISTANCE THERMOMETERS IN THE TEMPERATURE RANGE 11° TO 90°K

1951 ◽  
Vol 29 (2) ◽  
pp. 142-150 ◽  
Author(s):  
J. M. Los ◽  
J. A. Morrison
Keyword(s):  
Low Temperature ◽  
Temperature Scale ◽  
Platinum Resistance ◽  
National Bureau ◽  
International Temperature Scale ◽  
International Temperature ◽  
Platinum Resistance Thermometers ◽  
Resistance Thermometers ◽  
Corrective Term ◽  
Low Temperature Calorimetry

A set of six platinum resistance thermometers of a form suitable for low temperature calorimetry has been made and calibrated in the region 11° to 90°K. by intercomparison with a similar thermometer which had been calibrated at the National Bureau of Standards. Above 90°K. calibration has been made on the International Temperature Scale.Using the intercomparison data, it has been possible to derive a method whereby for these thermometers the scale for the region 20° to 90°K. may be found to within 0.002°C. by means of fixed points. The method applies a 'Z function' of the type used at the National Bureau of Standards (13), plus a corrective term which depends upon the resistance of the thermometer at the boiling point of hydrogen and upon the normal constants which are determined for the International Temperature Scale above 90°K.

Calibration and Application Techniques for Platinum Resistance Thermometers

1972 ◽  
Vol 94 (2) ◽  
pp. 381-386 ◽  
Author(s):  
R. P. Benedict ◽  
R. J. Russo
Keyword(s):  
Experimental Data ◽  
Temperature Scale ◽  
Calibration Procedure ◽  
Platinum Resistance ◽  
Platinum Resistance Thermometers ◽  
Resistance Thermometers ◽  
Application Techniques ◽  
Practical Temperature ◽  
Practical Temperature Scale ◽  
Resistance Thermometry

The International Practical Temperature Scale has been redefined recently. It follows that the interpolating equations relating platinum resistance to temperature must be reevaluated for all platinum resistance thermometers which are used as standards for calibration work. After a brief review of the former calibration procedure, the new temperature scale is discussed as it affects resistance thermometry in the temperature range from 0 C to 630.74 C. An example based on new experimental data is given to illustrate the method of determining thermometer constants for the new scale, and to indicate the magnitude of the changes required.

THE REPRODUCIBILITY OF THE SULPHUR POINT

1960 ◽  
Vol 38 (8) ◽  
pp. 1027-1047 ◽  
Author(s):  
R. J. Berry
Keyword(s):  
Boiling Point ◽  
Temperature Scale ◽  
Freezing Point ◽  
Impurity Content ◽  
Platinum Resistance Thermometer ◽  
Operating Conditions ◽  
Platinum Resistance ◽  
Resistance Thermometer ◽  
International Temperature Scale ◽  
International Temperature

The reproducibility of the normal boiling point of sulphur, a fixed calibration point on the International Temperature Scale, has been investigated using a closed manometer-boiler system. Measurements embracing several sources of sulphur and a number of changes in the operating conditions have shown that the sulphur point can be reproduced with a standard deviation of about 0.001 °C with our apparatus.Tests were made on eight samples of sulphur from three different sources in an attempt to resolve the uncertainty in the time the sulphur takes to reach temperature equilibrium after it has been brought to the boiling point. The results indicate that pure sulphur will reach equilibrium almost immediately but that an impurity content of as little as 0.01% can delay equilibrium up to 10 days. The temperature–time dependence can be ascribed to the effect of impurities on the time required for allotropic equilibrium to be attained. This hypothesis is discussed in detail and it is shown that it gives a consistent interpretation of the results presented here and those of previous investigations. The merits of replacing the sulphur point with the freezing point of zinc on the International Temperature Scale are also examined.The long-term stability of the coefficients of a Meyers platinum resistance thermometer is determined and a method of improving this stability for prolonged use at high temperatures is outlined.

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