Stability of Tungsten–Rhenium Thermocouples in the Range from 0 °C to 1500 °C

Ogura, H.; Izuchi, M.; Tamba, J.

doi:10.1007/s10765-011-1051-6

Cited by 14 publications

(7 citation statements)

References 6 publications

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“…Maximum offsets for both type are quite similar in magnitude, 4.8 C for Type A and -4 C for Type C. Ulanovskiy et al [5] reported that Type A thermocouples, when tested above 1350 C, generate larger EMF than is specified by the standard. Ogura [6] found similar behavior to that shown in figure 4 when they conducted aging at 1500 C. That is, the EMF of the Type C thermocouple initially increased and after 20 hours it began decreasing. At 100 hours of exposure time, the EMF was less than its initial value by more than 1 C. It is worth noting that thermocouple A52 exhibits minimal aging effect.…”

Section: Discussion Drift Due To Exposure To High Temperaturesupporting

confidence: 67%

Assessment of tungsten/rhenium thermocouples with metal-carbon eutectic fixed points up to 1500°C

Gotoh¹

2013

AIP Conference Proceedings

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Four Type A thermocouples and two Type C thermocouples were calibrated at the Au fixed point and Co-C and Pd-C eutectic fixed points. The thermocouples were exposed to 1330 ºC for a total of 100 hours. The maximum drift due to the exposure was found to be 4.8 ºC. The fixed-point calibration EMF of these thermocouples deviated by less than 0.86% from the temperature specified by the standards ASTM E230-2003 for Type C and GOSTR 8.585-2001 for Type A. The length of one of Type A thermocouples A52 is longer than the others by 150mm. Making use of this provision it was possible to place annealed part of A52 to the temperature gradient part of calibration arrangement every time. Therefore observed aging effect was as low as 0.5 ºC compared to the other thermocouples.

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Section: Discussion Drift Due To Exposure To High Temperaturesupporting

confidence: 67%

Assessment of tungsten/rhenium thermocouples with metal-carbon eutectic fixed points up to 1500°C

Gotoh¹

2013

AIP Conference Proceedings

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“…Usually, a W-Re thermocouple has a typical uncertainty of 1%, which is 20 °C at 2000 °C [1]. Under real operation, thermal drift of the W-Re thermocouple is always a serious issue, and it becomes increasingly severe as the temperature increases [2]. However, the drift behaviour of thermocouples is difficult to predict, and even thermocouples constructed from the same batch of thermocouple wire exhibit quite different performances.…”

Section: Introductionmentioning

confidence: 99%

Miniature fixed-point cells for self-calibration of type C high-temperature thermocouples

Sun¹,

Pan²,

Lu³

et al. 2019

Meas. Sci. Technol.

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A high-temperature tungsten-rhenium (W-Re) thermocouple is commonly used at temperatures up to 2000 °C for the high melting temperature of the thermoelement materials. When exposed to high temperatures, a thermocouple can show significant thermoelectric drift, which increases measurement uncertainty. The uncontrolled drift may come from the change in the crystallographic structure, oxidization of the thermoelement materials, interaction between the thermoelement materials and insulator materials and some other unknown reasons. Therefore, periodic recalibration of the thermocouple should be performed; however, sometimes it is not possible to remove the sensor out of the process, especially in some special fields, such as a nuclear power plant. Self-validation methods for thermocouples provide a solution to avoid this drawback. In this paper, miniature eutectic fixed-point cells are presented for self-validation of W-Re thermocouples. To prevent the breakage of the graphite crucible, these cylindrical miniature fixed-point cells contain several small independent crucibles and one thermocouple well, which increase the robustness of the miniature cell. The melting temperature was assigned by a radiation thermometer traced to the primary radiation standard at NIM. The effect of the temperature offset and temperature ramping rate on the melting temperature were checked. The performance of the miniature fixed-point cells and type C thermocouple, including characterization of the stability and repeatability, is presented.

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“…The lower output of the Land-Jewell thermocouple relative to the type B thermocouple, previously considered a drawback, is mitigated these days by the prevalence of very sensitive digital voltmeters, provided its use is restricted to temperatures in excess of 400 °C. As well as the advantage of its high melting temperature, its high Rh content relative to the letter-designated thermocouples lends it greater stability than the other Pt-Rh thermocouple types above about 1200 °C [2] and, in addition, its performance is far superior to the refractory metal W-Re thermocouples [3][4][5] under a wide range of conditions [6][7][8]. This is because alloys with high Rh content are less sensitive to local changes in Rh content caused by evaporation of the oxides of Pt and Rh which are very volatile at high temperatures [9,10].…”

Section: Introductionmentioning

confidence: 99%

A pan-European investigation of the Pt-40%Rh/Pt-20%Rh (Land–Jewell) thermocouple reference function

Pearce¹,

Elliott²,

Greenen³

et al. 2014

Meas. Sci. Technol.

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Accurate high temperature measurement has always been problematic for industry. The vast majority of industrial temperature measurements are performed with thermocouples. The development of any new thermocouple types requires the characterization of the relationship between thermocouple output and temperature, i.e. the reference function. An important thermocouple for measuring temperatures above about 1500 °C is the so-called Land–Jewell (Pt-40%Rh/Pt-20%Rh) thermocouple. This was used as a test thermocouple for a new European distributed facility for characterizing thermocouple reference function. The facility is described, and used to generate a demonstrator reference function for the thermocouple. It is found that the demonstrator reference function differs from the de-facto standard reference function of ASTM E1750-09 by several degrees above 1500 °C; a suggested explanation for this is given.

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Stability of Tungsten–Rhenium Thermocouples in the Range from 0 °C to 1500 °C

Cited by 14 publications

References 6 publications

Assessment of tungsten/rhenium thermocouples with metal-carbon eutectic fixed points up to 1500°C

Assessment of tungsten/rhenium thermocouples with metal-carbon eutectic fixed points up to 1500°C

Miniature fixed-point cells for self-calibration of type C high-temperature thermocouples

A pan-European investigation of the Pt-40%Rh/Pt-20%Rh (Land–Jewell) thermocouple reference function

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