University of Texas researchers and the Ford Motor Co. are collaborating on a spark plug that employs fiber to monitor pre-ignition fuel concentration. The goal, said developer Mathew Hall, is reduced engine pollutants and improved performance by analyzing fuel/air mixing. The sensors employs two fibers placed in the plug's ceramic core and a spherical mirror at the electrode to measure IR radiation absorbed by the fuel. IR radiation from a blackbody source is coupled into IR-transmitting fibers while a cryogenically cooled InSb detector completes the setup.