Glass electrode

摘要

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.