Abstract: The present invention is a multiplexer for use with an apparatus for optically analyzing a sample. This multiplexer includes a body portion having a primary inlet port. The light received through the light inlet port is sent through a first fiber optic bundle which may be rotated by a fiber carriage to any of several outlet fiber couplers which may be connected to various samples. A position optical sensor assures proper alignment between the first fiber optic bundle and the fiber couplers by sensing the position of a chopper disc which is mounted to the rotating fiber carriage. Once light is passed through the sample, it is passed back into the multiplexer through inlet fiber couplers. These additional fiber couplers are linked to a second fiber optic bundle leading to a detector fiber coupler which may be connected to a fixed fiber cable.

Abstract: An fixed grating, detector-array type analyzer rapidly multiplexes multiple channels. The analyzer comprises a light source, a detector array-type spectrograph, and an optical multiplexer. The multiplexer can select from one of a plurality of channels. Further, the multiplexer can convolute light passing through it with a reference spectrum for calibration and wavelength drift compensation. Rapid multiplexing is achieved using a fiber optic slit array which "perpendicularly multiplexes" the plurality of channels.

Abstract: A post hole digger and a method of implanting a post in the ground. A boring implement having a piercing free end and also having an attachment flange is secured to an end portion of a post to be implanted in the ground. The implement has a tapered body section with a projecting serrated edge on opposed sides thereof. The serrated edges extend angularly from a common longitudinal plane and in opposed angular directions. A pipe section is secured to the implement and a garden hose is connected thereto whereby to direct a stream of water in the direction of said piercing free end whereby axial rotation and counter-rotation of said post causes the implement to bore into the ground to cause said post to descend in a bore hole. After the post is implanted the garden hose is disconnected from the pipe section by applying a pulling force on the hose.