Abstract: An apparatus for optically detecting light-absorbing contamination in at least one particle of low optical-loss material comprises an optical integrating chamber for containing the particles. A laser for emitting a laser beam to illuminate the particles is mounted in the plane of rotation of a rotating mirror such that the laser beam scans in a fan scan. A scanning assembly is mounted in optical alignment with the laser for reflecting the laser beam and for causing the laser beam to scan the particles in the optical integrating chamber. A focusing assembly is mounted in optical alignment with the laser for focusing the scanning laser beam onto the particles in the chamber, the focusing assembly operating in conjunction with the scanning assembly so that light from the laser beam is reflected from the particles and is repeatedly scattered onto the interior walls of the integrating chamber.

Abstract: A gas fired radiant griddle assembly employing a series of perforated ceramic tiles to define a burner surface positioned beneath the griddle. The center area of the assembled ceramic tiles is blocked off so as to define an annular burner surface to minimize the temperature gradient across the griddle surface and the hot combustion effluents are drawn by convection beneath the griddle surface and out the rear corners of the combustion chamber beneath the griddle to heat the peripheral and corner portions of the griddle and further minimize the temperature gradient across the expanse of the griddle.

Abstract: An infrared heat device utilizing a ceramic burner tile operating in a confined combustion chamber. Inlet gas flow, metered by an orifice, is boosted as required by the air pressure provided in at least approximately Stoichiometric ratio to compensate for increased back pressure.

Abstract: A heat exchanger for use with a portable oven. The disclosed heat exchanger maximizes the conversion of heat caloric content of a combustible fuel to useable heat energy. A gas fueled infra-red burner mounted above the heat exchanger directs radiant energy toward a metal plate which also is contacted by waste or effluent from the burner. The metal plate in turn transmits heat by conduction to a sealed passageway or flow path through which air circulates on its way to the oven. By heating the plate with both effluent and radiation approximately 70% of the heat caloric content of the gas fuel is converted to heat energy for heating air in the passageway. Use of a sealed passageway allows conditions inside the oven to be controlled to make the oven suitable for use as a test oven.