The theoretical basis of heat flux sensor pen

Measuring heat flux out or into a process surface is of significant practical interest. Miniaturization of the sensor and the capability of dynamic sensing are highly desirable. In this paper, the theoretical basis of a heat flux sensor ‘pen’ idea has been established, which allows for real-time measurements. Here the thin temperature measuring wires (thermocouple) are used as the heat flux sensing and heat carrier device. Such a device is shown to be feasible with the available solutions obtained using a semi-empirical approach employing Laplace transformation method combined with an intermediate curve-fitting procedure in the case of finite sensor length and exact solution already available in literature in the semi-infinite domain case.