Abstract: A friction chuck for securing a test probe within a platform holder. The chuck, formed of elastomeric material, comprises a chuck body with an axially extending bore and a plurality of downward extending fingers disposed around the outer circumference of the projection of the chuck bore. Each finger has an interior bulge that extends into the projection of the chuck bore. The bulges define a segmented aperture of a diameter less than the diameter of the chuck base. When a test probe is inserted into the chuck bore it engages the fingers and bends them outwardly. There is sufficient friction between the fingers and the test probe so that the probe is secured by the fingers. The fingers have sufficient flexibility so the probe position may be changed by hand adjustment.

Abstract: An improved electrode for detecting ion concentration and a method of manufacturing such an electrode. The electrode includes concentric glass tubes, including an inner tube which is filled with a filling solution and a larger, outer tube which extends above the level of the filling solution in the inner tube. A metal contact is immersed in the filling solution and extends outside the inner tube through a hermetic seal to allow electrical contact to be made to the filling solution. The inner tube is made of a different glass from the outer tube so that the inner tube will absorb radiation at selected wavelengths which are transmitted by the outer tube. The inner tube is illuminated with radiation of the proper wavelength so that the inner tube melts and collapses around the metal contact to form the hermetic seal. In an alternate embodiment, the electrode has an inner tube which is made of two different types of glass. An apparatus for mechanizing the electrode sealing process is also described.

Abstract: Apparatus for calibrating an ion analyzer comprises a calibration cell having defined therein a first volume for measuring an ion concentration of a sample when the instrument is operated in a monitoring and a second volume for measuring the ion concentration when the instrument is operated in a calibration mode. The first volume is included in, and forms part of, the second volume so that the matrix for the calibration measurement is essentially identical to that for the sample measurement. A double known-addition is used during the calibration mode to determine the calibration parameters.

Abstract: An improved electrochemical reference electrode for use in potentiometric determinations of species in solution. The body of the electrode is composed of a material substantially permeable to liquid water whose exterior surface, excepting a comparatively small area, is covered by a membrane through which water may pass only by diffusion and which is also ion impermeable. The small area which is not covered forms an opening through the membrane to the body. The body contains a saturated salt slurry. When the electrode is immersed in an aqueous sample solution, water diffuses through the membrane and is transported in bulk across the body. Upon entry into the slurry, the water dissolves the solid salt in the slurry to produce an electrolyte which in turn flows outward through the small area of the body which is not covered by the membrane, whereby a liquid junction is provided between the electrolyte and the sample solution.