Novel noncontact temperature fiber sensor for multi-spot field measurements

The present paper shows the results of a new development in the field of industrial contactless temperature measurement typically in the range of 650 K up to 1200 K. Using fiber optics, the new sensor head has a small size matching the requirements for integration in demanding applications. The sensor delivers an irradiance dependent signal of the targeted (metallic) surface under test together with the acquired distance in the same measuring spot and the corresponding surface reflectivity. Thus a simple processing unit can calculate in realtime the emissivity and the influence of the measuring distance on the temperature measurement. The target application of this sensor is a multi-spot temperature profile acquisition for on-line monitoring of joining processes (welding, brazing, etc.) or any heat affected metal processing including the case of low-emissivity materials like Aluminum.