RADIATION EFFECTS IN PRECISION RESISTANCE THERMOMETRY: II. ILLUMINATION EFFECT ON TEMPERATURE MEASUREMENT IN WATER TRIPLE-POINT CELLS PACKED IN CRUSHED ICE

1966 ◽  
Vol 44 (11) ◽  
pp. 2653-2659 ◽  
Author(s):  
E. H. McLaren ◽  
E. G. Murdock
Keyword(s):  
Triple Point ◽  
Radiation Effects ◽  
Near Infrared ◽  
Radiation Shielding ◽  
Platinum Resistance ◽  
Platinum Resistance Thermometers ◽  
Resistance Thermometers ◽  
Temperature Errors ◽  
Crushed Ice ◽  
Water Triple Point

The heating effect of normal laboratory illumination on the sensors of standard platinum resistance thermometers immersed in a standard water triple-point cell packed in crushed ice has been investigated. This study shows that the absorption by the platinum sensors of luminous and near-infrared radiation transmitted through the ice pack could easily amount to temperature errors as large as 0.000 5 °C. Any illumination error must be eliminated by making all measurements in the dark or under adequate radiation shielding.

RADIATION EFFECTS IN PRECISION RESISTANCE THERMOMETRY: I. RADIATION LOSSES IN TRANSPARENT THERMOMETER SHEATHS

1966 ◽  
Vol 44 (11) ◽  
pp. 2631-2652 ◽  
Author(s):  
E. H. McLaren ◽  
E. G. Murdock
Keyword(s):  
Radiation Effects ◽  
Near Infrared ◽  
Platinum Resistance Thermometer ◽  
Fused Silica ◽  
Platinum Resistance ◽  
Resistance Thermometer ◽  
Fixed Temperature ◽  
Radiation Losses ◽  
Platinum Resistance Thermometers ◽  
Resistance Thermometers

Standard platinum resistance thermometers that are constructed with transparent sheaths of fused silica or pyrex glass are subject to thermal losses arising from losses of visible and near-infrared radiation up (piping) and through these sheaths. This heat loss may introduce substantial errors in temperature determinations; e.g. 0.084, 0.015, and 0.001 1 °C at the Sb, Zn, and Sn fixed-temperature points for a fused-silica sheath, or 0.000 2 °C at the Zn and Sn points for a pyrex sheath. This effect has been investigated in detail for thermometers of various types at the Sb, Zn, and Sn points, and it has been shown that simple stem radiation-traps, consisting of a blackening or roughening of the smooth outer surface of the thermometer sheaths, will eliminate these errors and greatly improve the immersion characteristics of the thermometers.Suitable radiation-trapping should be incorporated on the stems of every transparent-sheathed standard platinum resistance thermometer; without strong evidence to the contrary, radiation loss errors of the orders of magnitude cited above should be suspected in reported measurements involving resistance thermometers having unprotected transparent fused-silica sheaths.

THE FREEZING POINTS OF HIGH PURITY METALS AS PRECISION TEMPERATURE STANDARDS: I. PRECISION MEASUREMENTS WITH STANDARD RESISTANCE THERMOMETERS

1957 ◽  
Vol 35 (1) ◽  
pp. 78-90 ◽  
Author(s):  
E. H. McLaren
Keyword(s):  
Triple Point ◽  
Cold Work ◽  
Platinum Resistance ◽  
Intrinsic Resistance ◽  
Long Term Stability ◽  
Resistance Bridge ◽  
Platinum Resistance Thermometers ◽  
Resistance Thermometers ◽  
Precision Temperature

The techniques and difficulties encountered in measuring temperatures to the highest precision with platinum resistance thermometers are discussed. It is shown that the relative drift of the resistance coils in the Mueller resistance bridge used for these measurements is less than a part per million per year. The intrinsic resistance of a platinum thermometer is comparatively unstable, and results showing some effects of cold work and heat treatment on several thermometers are given.As each precision temperature determination involves the resistance of the thermometer at the triple point of water, extensive measurements have been carried out to obtain information on: (a) the reproducibility of temperature in particular cells, (b) the variation in temperature among cells, and (c) the long term stability of cell temperatures.The limiting uncertainties in temperature measurements due to variation in the bridge, the thermometers, and the triple point cells are each of the order of 10−4 °C.

Triple point of gallium used to calibrate low-temperature platinum resistance thermometers

1991 ◽  
Vol 34 (5) ◽  
pp. 466-468 ◽  
Author(s):  
Ya. E. Razhba ◽  
I. A. Razhba
Keyword(s):  
Low Temperature ◽  
Triple Point ◽  
Platinum Resistance ◽  
Platinum Resistance Thermometers ◽  
Resistance Thermometers

Certifying precision platinum resistance thermometers

1990 ◽  
Vol 33 (6) ◽  
pp. 586-588
Author(s):  
S. L. Knina ◽  
A. A. Nechai ◽  
A. A. Semenov ◽  
V. A. Petrushina ◽  
A. I. Pokhodun
Keyword(s):  
Platinum Resistance ◽  
Platinum Resistance Thermometers ◽  
Resistance Thermometers

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.

Sign in / Sign up

Export Citation Format

Share Document