Abstract: The object of the invention is to provide an analytical instrument (25) for use with profile diagrams (1) of materials to monitor and determine whether the detection systems producing such profile diagrams (1) are functioning properly, and to quickly pin-point and identify, among known materials exhibited by such profile diagrams (1), unknown materials exhibited by such profile diagrams (1).Said analytical instrument (25) has a flat, rectangular-shaped body (29) with three horizontal and parallel slots (61), (63) and (65) formed therethrough and markers (43) of different colors that are adjustably disposed relative to such slots (61), (63) and (65) and secured therewith. Such markers (43) are adjustably disposed respecting a profile diagram (1) to pin-point the materials profiled by such profile diagram (1) with the colored markers (43) being used thereby as color-coded reference markers for known materials profiled.

Abstract: A response tracer audio equalizer booster amplifier unit having graphic display of frequency response characteristics for variably boosting the power of output signals from an audio frequency signal source to speakers of a stereo sound system or the like, having a cabinet enclosing audio amplifier circuitry for variably boosting the audio signal at plural frequency bands in the audio spectrum, a manually adjustable slide control for each band adjustable along horizontal fore-and-aft paths for varying the signal boosting at the frequency bands, and a graphic display window having markings for the frequency bands and a continuous flexible curve indicator wire variably shaped to simulate a frequency response curve. Motion translating flexible coupling members are moved by the slide to shape the wire to indicate the frequency response curve.

Abstract: A game card assembly consisting of a plurality of superposed sheets which define a plurality of windows in vertical, horizontal, and diagonal rows, each window being provided with two laterally slidable shutters which are selectively movable back and forth between retracted substantially non-visible positions and predominately visible positions. The shutters of each window possess different distinguishing characteristics so that when either shutter is in its predominately visible position, its window as a whole is given a distinguishing characteristic. The various rows of windows are arranged in checkerboard fashion in order that vertical, horizontal or diagonal alignment of like shutters may form the basis for the playing of a game of the tic-tac-toe variety.