NPL have teamed up with RAL Space to investigate calibration options for the thermocouples, such as using a very small ingot of gallium to provide a known, and reliable, reference temperature which can provide an in-situ calibration of the resistance thermometers that is traceable to the ITS-90. The melting temperature of gallium is well established.
NPL have been able to show that the miniature ingot can be used in this situation, and with as little as 0.5 g of metal. It is suitable for possible inclusion in a flight mission.
With this new technology in place, it is expected that there will be significant improvements in the accuracy, stability and traceability of temperature measurements in the space sector, which in turn will underpin climate studies.
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Read more about non-contact thermometry