Abstract: The body of an ion-sensitive electrode is formed from a bulb (32) of an ion-selective material that is transparent to infrared radiation. A glass tube (12) made of material that absorbs infrared radiation is inserted into the bulb, and a source (15) of infrared radiation is focused through the bulb (32) onto the end of the tube (12) on which the bulb (32) rests. The resultant heating causes the tube and the bulb to fuse together, and the portion of the bulb outside the tube is then removed to result in an electrode body (FIG. 4).

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.