Abstract: A low maintenance reference electrode has a liquid junction body with a multiplicity of micron-sized capillary channels extending through the body for transporting electrolyte to a test solution. A viscosity-increasing agent thickens the electrolyte to limit its flow to a rate on the order of microliters/day so that a few milliliters of electrolyte suffice to provide an extended electrode life.

Abstract: An improved combination ion-selective electrode has a thin ion-sensing body extending from an outer reference body. The exposed portion of the ion-sensing body is encompassed by a sleeve which effectively forms an extension of the reference body and also provides mechanical stability to the ion-sensing body. One or more fluid channels are formed interior to the sleeve to provide an electrically conductive path from the reference solution within the reference body to the tip of the electrode.

Abstract: A measurement/calibration cell for potentiometrically measuring ion concentration in a fluid interposes a barrier between measuring and reference electrodes and positions the measuring electrode at a sufficiently higher gravimetric potential above the reference electrode that seepage of electrolyte from the latter to the former is effectively precluded. A controller associated with the cell displays instructions and other desired information on a scrolling display such that a substantial amount of information can be presented in a relatively small display window.

Abstract: A compact multiparameter instrument for electrochemical measurements is described. The instrument facilitates rapid engagement and disengagement of a variety of sensor elements in such a manner as to prevent accidental mismatch of sensor elements and sensor input ports. Positive identification of specific sensors is ensured by including color marking or other indicia on the sensor connectors that are matched to corresponding markings on the meter body. Measurements of specific parameters such as temperature may readily be shared among all other sensors connected to the instrument. A method of rapidly reconfiguring the instrument to provide extended or different capabilities is described.

Abstract: Disclosed are combination glass pH electrodes, the standard potential of which is stabilized by means one or more of the following structural modifications: (a) incorporating a noble metal internal element in the pH half-cell; (b) incorporating a noble metal internal element in the reference half-cell; (c) incorporating an internal pH bulb electrolyte with stable pH and oxidation-reduction potential; (d) incorporating an homogenous reference electrolyte with stable oxidation-reduction potential and equitransferent salt; (e) incorporating a liquid junction composed of a porous, inert material; (f) incorporating a reference electrolyte compartment vent; (g) incorporating a storage sleeve, with or without an absorbent medium located therein.