Abstract: A device for conditioning air has a pad formed of a plurality of layers of slit and expanded media, with the pad having a plurality of groups of layers therewithin. Each layer within a particular group of layers has its baffles oriented to face in the same direction, while each group is turned around to face in the opposite direction from its directly adjacent group so that the baffles of one group face oppositely to the baffles of the next adjacent group. Alternate layers within each group are expanded to a slightly different degree so that the various elements making up each layer support the elements of adjacent layers in spaced unnested relationship. The dimensions of the expanded cells are substantially greater than those of known prior pads to better accommodate higher air velocities.

Abstract: 1. An oscillator-detector circuit comprising operating potential energy rces, first self pulsing circuit means intermittently oscillatory for developing high frequency electromagnetic energy pulses of a preselected carrier frequency and repetition rate, electromagnetic energy radiating means electrically coupled to said first circuit for effecting radiation of said developed pulses into space and for receiving any reflected electromagnetic pulses, and a second oscillatory circuit means inductively coupled to said first circuit means and being rendered intermittently oscillatory during the occurrence of said developed pulses for selectively detecting variations in the magnitudes of said developed pulses caused by said reflected pulses and for developing an output signal having a frequency correlative to said variations, said first and second oscillatory circuits being parallel connected across said energy sources.