Measuring timing properties of thermal infrared cameras

A measurement setup and method is presented that is serves to determine constants characterising the timing behaviour of thermal infrared cameras. A continuously rotating chopper wheel is used to periodically obscure and reveal the cutout of a mask plate. The exposed fraction of the cutout is the main measured quantity. Irregularities in the chopper wheel are determined from timestamps of the light beam detectors in the chopper head. The method is suitable for both kinds of thermal cameras, cooled cameras and microbolometer cameras, and for both snapshot and rolling-frame cameras. Example results are presented for a cooled snapshot camera and a rolling-frame microbolometer camera.