The adapter Part No. 830-00014 screws onto the special probe Part No. 630-0217 at the nodal point. The glass chamberslides onto the adapter and is secured in place as the bushing is screwed into the chamber compressing the O-ring. Movingthe glass chamber up or down on the adapter allows the portion of the probe protruding out of the adapter to be immersedat the optimum depth into the sample.