Bench-scale test facility for evaluating the performance of thermal imagers for fire service applications

A bench-scale facility was developed for the evaluation of thermal imaging cameras. Smoke obscuration conditions in the optical smoke cell were characterized by measuring laser light transmittance through the cell. Measurements showed that the laser transmittance along the axial direction of the optical smoke cell was relatively uniform in the upper and lower halves of the cell for various smoke obscuration conditions. The thermal sensitivity of thermal imagers was investigated using the Michelson Contrast as a performance metric for a bar target viewed through the smoke-filled cell for different background thermal conditions. The results of the study indicate that the optical smoke cell can be utilized as a well-controlled and effective bench-scale test apparatus to evaluate aspects of the performance of thermal imagers for fire service applications.