Abstract: A manually-rotatable switch knob is provided on the alhidade of a sextant that is connected to a switching pin of hardened steel arranged eccentrically to the mounting of the knob. The switching pin engages the drum-screw mounting and, under the action of a stop spring, permits the drum screw to be switched back and forth between two stable stop locations when the knob is rotated. In the one stop location, the drum screw engages the limbus toothing. In the other location, the drum screw is completely disengaged from the limbus toothing so that the alhidade can be freely pivoted without risk of the drum screw damaging the limbus toothing during the movement of the alhidade. The stop spring also produces precisely defined contact pressure between the drum screw and the limbus toothing. The previously possible introduction of bending moments into the alhidade during rough adjustment is eliminated.

Abstract: A method and means for a spatial and temporal probe for laser generated plumes based on density gradients includes generation of a plume of vaporized material from a surface by an energy source. The probe laser beam is positioned so that the plume passes through the probe laser beam. Movement of the probe laser beam caused by refraction from the density gradient of the plume is monitored. Spatial and temporal information, correlated to one another, is then derived.

Abstract: For use in a spectrophotometry or spectrofluorimetry system, where a fluid to be analyzed, is passed into or through a tube having at least one branch, a plastic device insertable into said branch, said device comprising a tubular plastic member the inner end of which is closed by a transparent transverse end wall, extending into the tube branch and within which an end of a fiber optic cable is removably secured with such end disposed in facing engagement with the inside of said wall, and a detector cap defining a chamber to hold some of the fluid or a dye color reactive to such fluid, is secured on the opposite side of the end wall. The tubular plastic member is removably securable in, and closes the tube branch.