Traceable and standardized metrology for thermoelectric generator modules (TEM) is a mandatory element for an industrialization of thermoelectric applications. High measurement deviations >20% have been observed in inter-laboratory tests on TEM properties. Such uncertainties are too high for scientific studies and seem insufficient to validate industrial benchmarks. Particularly, works on hightemperature TEM have to be supported by appropriate characterization techniques. This shall accelerate progress towards product releases for thermoelectric energy conversion.
Standardization of metrology for thermoelectric generator modules (TEMs) is a necessary step toward industrialization of thermoelectric applications. Unspecified uncertainty budgets of the widely used custom‐built characterization facilities seem insufficient to validate technological developments, industrial benchmarks, or allow sound conclusions in scientific studies. Particularly, works on high‐temperature TEM have to be supported by suitable characterization techniques. This shall accelerate progress toward product releases for thermoelectric energy conversion. Herein, a Ni‐based alloy TEM is reported, which is developed at the National Institute of Advanced Industrial Science and Technology (AIST) as a prospective standard reference TEM. Comparative measurements at AIST and the German Aerospace Center (DLR) demonstrate the high repeatability and precision of custom‐built TEM characterization facilities at AIST and DLR. Tests at elevated temperatures up to 773 K hot side temperature and 450 K temperature difference reveal excellent accordance of electric measurands with a standard deviation <0.3% for the open‐circuit voltage and <0.85% for electric resistance and maximum power output. Deviations of the heat flow measurement of up to 7.22% arise from individual uncertainties of the used characterization methods and point to the importance of standardization for TEM metrology.
The status of metrology for the characterization of thermoelectric generator modules (TEM) is investigated in this work by an international round robin (RR) test including twelve laboratories from nine countries on three continents. Measurements have been performed with three samples of a Bi2Te3-based commercial TEM type, which has prevailed over three competing types during previous tests on the short- and long-term stability. A comparison of temperature-dependent results is provided up to 200 °C hot side temperature for the maximum power output Pmax, the incident heat flow Q˙In (at maximum efficiency conditions), and the maximum efficiency ηmax. Data evaluation from all RR participants reveals maximum standard deviations for these measurands of 27.2% (Pmax), 59.2% (Q˙In), and 25.9% (ηmax). A comparison between RR data sets and reference data from manufacturer specifications shows high deviations of up to 46%, too. These deviations reflect the absence of measurement guidelines and reference samples and confirm the need for improvements in the standardization of TEM metrology. Accordingly, the results of the RR are presented against the background of our own investigations on the uncertainty budgets for the determination of the abovementioned TEM properties using inhouse-developed characterization facilities, which comprise reference and absolute measurement techniques for the determination of heat flow.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.