Large-Area, High-Sensitivity Heat-Flow Sensor

A heat-flow sensor based on ac resistance thermometry and utilizing synchronous detection is described. The sensor design permits large-area sensors to be constructed economically. Calibration of an initial 0.09 m² prototype yielded a linear response with a sensitivity of (37.6±0.01) mV(W/m²)^-1. The minimum detectable heat flux is no larger than 0.08 W/m².