Abstract: In order to provide a lead free and environmental friendly glass electrode, a glass electrode has a responsive glass membrane conjugated with a distal end portion of a stem glass tube. Neither lead nor a lead compound is included in the stem glass tube and one of an alkali metal oxide and an alkali earth metal oxide is provided so that a thermal expansion coefficient of the stem glass tube is within ±20% of that of the glass used for the responsive membrane.

Abstract: In order to provide a lead free and environmental friendly glass electrode, a glass electrode has a responsive glass membrane conjugated with a distal end portion of a stem glass tube. Neither lead nor a lead compound is included in the stem glass tube and one of an alkali metal oxide and an alkali earth metal oxide is provided so that a thermal expansion coefficient of the stem glass tube is within ±20% of that of the glass used for the responsive membrane.

Abstract: An ion concentration measuring electrode unit includes a body member having a plurality of capillary tubes extending through the body member to provide a plurality of passageways for a sample fluid to be tested. The gaps between the hollow tubes are sealed to maintain an internal solution complimentary to the ion to be measured. An internal electrode is immersed within the internal solution whereby a large internal surface area is provided to enable a reduced impedance in measurement of a sample fluid. An ion concentration meter assembly is thereby provided when combined with a sample flow conduit directing fluid through the body member with a liquid junction connected to the conduit and to a reference electrode unit whereby outputs of the internal electrode and a reference electrode can be used to measure an ion concentration.

Abstract: A flow injection nonaqueous solvent neutralization titration process and system is provided. The predetermined quantity of a known titrant is used to derived calibration values based on different predetermined concentrations of a desired component in a sample. The quantity of the titrant agent in excess of an amount necessary to completely react with the sample is added and then subsequently the amount of the unreactant titrant agent is determined. From this value, the calibration values that have been stored, for example, in a look-up table can be used to determine the actual concentrations of the desired component in the sample.