A new type of ring-shaped temperature sensor for packed-bed heat transfer studies is presented. This ring-shaped sensor is easy-to-build and allows one to filter the experimental angular temperature fluctuations. This device is more effective for beds of small tube-to-particle diameter ratio. The proposed device is able to eliminate the effect of the angular position on temperature measurements in packed beds. This sensor property is confirmed both experimentally and theoretically. For demonstration purpose, packed beds of six different materials were studied. Effective thermal radial parameters obtained using the ring-shaped sensors have shown trends similar to published packed-bed heat transfer data.