Abstract: A catalytic bed has an upright forward surface openly exposed to the living space and generates a partially laminar flow and a partially turbulent flow of substantially smokeless gaseous combustion products upward along the bed surface, with laminar flow adjacent thereto and the turbulent flow positioned forward thereof. A collection chamber is positioned above the bed and has spaced apart lower and upper walls to define a rearward collection chamber and a forward inlet space. A negative pressure source is connected to the collection space to create an exhaust flow therefrom. A baffle wall extends laterally and projects upwardly from the lower wall toward the upper wall, terminating at a distance therefrom to create a pressure drop between the collection and inlet spaces sufficient to provide a substantially uniform draw along the length of the baffle wall.

Abstract: A weighing device using an electromagnet to attract a load bearing member where the balancing force is sensed using a Hall effect device to sense the force of the magnetic field. Means are provided to produce a signal which is linearly proportional to the weight of the object being weighed.