Development of a Standard Reference Thermoelectric Module: Enhancing Durability and Reproducibility through Metallic...

Reliable standard modules are critical to ensure reproducibility and comparability in thermoelectric measurements across research laboratories. In this study, the development of a standard reference thermoelectric module (SRTEM) is presented to address this unmet need by providing a reproducible calibration platform for cross-laboratory thermoelectric measurement standardization. The SRTEM comprises eight p-n thermocouple pairs formed from metallic alloys─p-type Ni₉₀Cr₁₀ (Chromel) and n-type Cu₅₅Ni₄₅ (Constantan) or Ni₉₅Al₂Mn₂Si₁ (Alumel)─selected for their mechanical durability and bonding compatibility. To increase thermal resistance and ensure the consistent voltage output, a "hollow hourglass"-shaped leg geometry was adopted, reducing the effective leg cross-section while maintaining structural integrity. This design yielded an open-circuit voltage (V_oc) of 89 mV, achieving a 32.8% improvement over conventional rectangular-leg modules under identical thermal gradients. Direct metal-to-metal bonding without metallization layers resulted in stable electrical contact with low contact resistance. Furthermore, the SRTEM maintained consistent performance over 300 thermal cycles (∼210 h), with no observable degradation in V_oc or key output metrics. These results establish the SRTEM as a scientifically validated and practically deployable reference standard, paving the way for standardized, highly reliable thermoelectric evaluations in both academic and industrial settings.