Coaxial Thermocouple Performance Evaluation

This white paper presents an evaluation of the performance of Ahmic’s coaxial thermocouples (TCs) through experimental testing in shock tube and shock tunnel environments. The objective is to demonstrate the capabilities of these TCs in providing accurate surface temperature measurements during transient heating scenarios. The paper outlines the operating principle of coaxial TCs, which utilize the Seebeck effect to generate a temperature-dependent voltage. It details the construction of the TCs, emphasizing the thin junction design that allows for rapid thermal response. The results from the shock tube tests indicate that Ahmic’s TCs perform well compared to industry-standard sensors, showing strong agreement in temperature and heat flux measurements. Additionally, the paper describes the shock tunnel tests, where various sensor types were compared under high-enthalpy conditions. The findings suggest that Ahmic’s coaxial TCs are effective for capturing unsteady surface temperature data, making them suitable for hypersonic testing applications.