Effects of Quartz Glass Insulation on Platinum Gold Thermocouples

Abstract Au/Pt thermocouples are considered as an alternative to High Temperature Platinum Resistance Thermometers and are one of the prime candidates to replace them as the interpolating instrument of the International Temperature Scale of 1990 (ITS-90) in the temperature range between about 660 °C and 962 °C. This work presents the results of investigation of two Au/Pt thermocouples that used exclusively quartz glass (SiO2) as insulation material. Measurements in fixed points of Zn, Al, and Ag were realized on these thermocouples as well with interchanged inner insulation made of high purity aluminium oxide (Al2O3). The conducted experiments tested the performance of Au/Pt thermocouples with the use of different insulation materials. The measured electromotive forces were found to be sensitive to the replacement of the quartz glass by aluminium oxide as an insulation material of the Au/Pt thermocouples. This change of insulation has resulted in a temperature increase up to about 0.5 K measured at the freezing point of silver. The decreasing insulation resistance of quartz glass at higher temperatures is believed to be the source of thermoelectric instability.

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A method for indirect measurements of the parameters of platinum resistance thermometers at the freezing point of silver

Measurement Techniques ◽

10.1007/s11018-005-0068-2 ◽

2004 ◽

Vol 47 (11) ◽

pp. 1100-1105

Author(s):

S. V. Marinko

Keyword(s):

Freezing Point ◽

Platinum Resistance ◽

Indirect Measurements ◽

Platinum Resistance Thermometers ◽

Resistance Thermometers ◽

Freezing Point Of Silver

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Effects of Pretreatment and the First Anodization Time on Morphology of Anodic Aluminium Oxide Templates

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.181-182.707 ◽

2011 ◽

Vol 181-182 ◽

pp. 707-711 ◽

Cited By ~ 2

Author(s):

Yu Cheng Wu ◽

Jie Wu Cui ◽

Yan Wang ◽

Guang Qing Xu ◽

Xin Yi Zhang

Keyword(s):

Aluminium Oxide ◽

Sem Images ◽

Anodization Time ◽

Effect Mechanism ◽

Anodic Aluminium Oxide ◽

Purity Aluminium ◽

High Purity Aluminium ◽

Aluminium Sheets ◽

Anodization Method ◽

Scanning Electron

Anodic aluminium oxide(AAO) templates were fabricated by a two-step anodization method utilizing high purity aluminium sheets. On the basis of getting the optimum preparation parameters of AAO templates, effects of the pretreatment and the first anodization time on morphology of AAO templates were studied. Field emission scanning electron microscope(FESEM) was used to investigate surface morphology of AAO templates. The SEM images indicated that both pretreatment and the first anodization time had a significant influence on morphology of AAO templates. Meanwhile,effect mechanism of pretreatment and the first anodization time on AAO templates morphology was elucidated.

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

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1958.0179 ◽

1958 ◽

Vol 247 (1249) ◽

pp. 214-224 ◽

Cited By ~ 4

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.

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