Melting points of gallium and of binary eutectics with gallium realized in small cells

Burdakin, A.; Khlevnoy, B. B.; Samoylov, M. L.; Sapritsky, Victor I.; Ogarev, S. A.; Panfilov, A. S.; Bingham, Gail E.; Privalsky, Victor; Tansock, Joseph J.; Humpherys, Thomas

doi:10.1088/0026-1394/45/1/011

Cited by 37 publications

(18 citation statements)

References 9 publications

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“…4,5 The purpose of these studies was to significantly reduce the size and volume of qualified containers and identify PCMs within the range of 273-303 K that could be used as calibration standards aboard Earth-observing satellites. This study was successful in identifying and characterizing several suitable eutectics to fill the gap in the ITS-90 temperature scale between the triple point of water and the melting point of Ga. SDL has continued research to further reduce the size and minimize volume of PCMs for an orbital thermal reference cell.…”

Section: Introductionmentioning

confidence: 99%

Observational study: microgravity testing of a phase-change reference on the International Space Station

et al. 2015

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BACKGROUND: Orbital sensors to monitor global climate change during the next decade require low-drift rates for onboard thermometry, which is currently unattainable without on-orbit recalibration. Phase-change materials (PCMs), such as those that make up the ITS-90 standard, are seen as the most reliable references on the ground and could be good candidates for orbital recalibration. Space Dynamics Lab (SDL) has been developing miniaturized phase-change references capable of deployment on an orbital blackbody for nearly a decade. AIMS: Improvement of orbital temperature measurements for long duration earth observing and remote sensing. METHODS: To determine whether and how microgravity will affect the phase transitions, SDL conducted experiments with ITS-90 standard material (gallium, Ga) on the International Space Station (ISS) and compared the phase-change temperature with earth-based measurements. The miniature on-orbit thermal reference (MOTR) experiment launched to the ISS in November 2013 on Soyuz TMA-11M with the Expedition 38 crew and returned to Kazakhstan in March 2014 on the Soyuz TMA-10 spacecraft. RESULTS: MOTR tested melts and freezes of Ga using repeated 6-h cycles. Melt cycles obtained on the ground before and after launch were compared with those obtained on the ISS. CONCLUSIONS: To within a few mK uncertainty, no significant difference between the melt temperature of Ga at 1 g and in microgravity was observed. INTRODUCTIONThe Committee for Earth Science and Applications from Space has articulated a scientific need for orbital temperature knowledge to support infrared radiance measurements with 0.1-K uncertainty 1 over a period of at least 10 years. As temperature uncertainty is only one of the contributors to the desired 0.1-K uncertainty, the goal for on-orbit temperature knowledge must be smaller (in the range of 0.01 K) to leave margin for other uncertainties in the calibration chain. Onboard references utilizing phase transitions have been identified as the most likely means for realizing International System of Units (SI) traceability for temperature measurements in orbit.The 3) identifies several phase-change materials (PCMs) with reliable fixed points that can be reproduced and used as references with submilli-kelvin absolute uncertainties for ground-based calibrations. Three PCMs with fixed points in the range required to calibrate Earth-observing sensors are gallium (Ga), water, and mercury with melt points of 302.9146, 273.16, and 234.3156 K, respectively. 3 However, the ITS-90 description of procedures and apparatuses does not translate easily into a design for an automated orbital implementation. ITS-90 describes fixed-point cells that use fragile materials such as plastic or glass to contain PCMs and require sensors to be placed in reentrant wells within relatively large volumes of 250 ml or more of the PCM. The described procedures do not apply directly to in situ sensor calibrations such as those that will be required on an orbital blackbody.In early 2006, the suitability of ...

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Section: Introductionmentioning

confidence: 99%

Observational study: microgravity testing of a phase-change reference on the International Space Station

et al. 2015

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“…1-3 and in Table 3. Detailed description of the experiments and their results are described elsewhere [23]. The results obtained in that study and shown partially in this paper show that these substances present a definite interest for further studies of fixed points in small cells under the orbital conditions.…”

Section: Suggestions For Problem Solutions and Further Stepsmentioning

confidence: 52%

Metrological support for climatic time series of satellite radiometric data

Sapritsky

Burdakin

Khlevnoy

et al. 2009

J. Appl. Remote Sens

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A necessary condition for accumulating fundamental climate data records is the use of observation instruments whose stability and accuracy are sufficiently high for climate monitoring purposes; the number of instruments and their distribution in space should be sufficient for measurements with no spatial or temporal gaps. The continuous acquirement of data over time intervals of several decades can only be possible under the condition of simultaneous application of instruments produced by different manufacturers and installed on different platforms belonging to one or several countries.The design of standard sources for pre-flight calibrations and in-flight monitoring of instruments has to meet the most stringent requirements for the accuracy of absolute radiometric measurements and stability of all instruments. This means that the radiometric scales should be stable, accurate, and uniform.Current technologies cannot ensure the high requirements for stability and compatibility of radiometric scales: 0.1% per decade within the 0.3 -3 µm band and 0.01 K per decade within the 3 -25 µm band.It is suggested that this task can be aided through the use of the pure metals or eutectic alloy phase transition phenomenon that always occur at the same temperature. Such devices can be used for pre-flight calibrations and for on-board monitoring of the stability of radiometric instruments. Results of previous studies of blackbody models that incorporate phase transition phenomenon are quite promising. A study of the phase transition of some materials in small cells was conducted for future application in onboard monitoring devices and its results are positive and allow us to begin preparations for similar experiments in space.

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“…Multi-component alloys are more complex than pure metals, and previous studies [5][6][7] have shown that the eutectic fixedpoint temperatures should be determined in accordance with their melting temperatures just like the gallium melting point of the ITS-90. Two factors are relevant for the reproducibility of the fusion temperature: the solidification process and the oven setup for melting the eutectic [8].…”

Section: Melting Point Productionmentioning

confidence: 99%

“…Gallium has a tendency for deep supercooling during the freezing stage, and this property is shared by gallium-based fixed points. Although there are experimental results [7] that suggest that it is possible to avoid supercooling (and then work with temperatures closer to transition), we wanted to be absolutely sure that the Ga-In mixture would solidify completely. For this reason, we followed the procedure below to obtain the melting point:…”

Section: Melting Point Productionmentioning

confidence: 99%

Eutectic Ga-In Melting-Point Blackbody for Radiation Thermometry

Sastre-Muñoz

Cárdenas-García

2015

NCSLI Measure

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The Radiation Thermometry Group at the Centro Nacional de Metrología (CENAM) is presently working with low-temperature fixed-point blackbodies to study their suitability for calibration and verification of radiation thermometers. The International Temperature Scale of 1990 specifies two fixed points in the 0 ºC to 30 ºC temperature range: the triple point of water and the melting point of gallium. We designed a eutectic Ga-In melting-point blackbody that could serve as a good candidate as a third fixed-point in the middle of those fixed points. The measured radiance temperature of the eutectic Ga-In melting-point blackbody was 15.67 ± 0.10 ºC (k = 1).

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Melting points of gallium and of binary eutectics with gallium realized in small cells

Cited by 37 publications

References 9 publications

Observational study: microgravity testing of a phase-change reference on the International Space Station

Observational study: microgravity testing of a phase-change reference on the International Space Station

Metrological support for climatic time series of satellite radiometric data

Eutectic Ga-In Melting-Point Blackbody for Radiation Thermometry

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