Combination pH electrode

Claim 1

A combination electrode for measuring pH values, comprising; a central body having a glass electrode receiving recess therein with a contact pin having a lead pin receiving recess therein at the internal end of said glass electrode receiving recess; a glass electrode having a glass membrane, an internal electrode in said glass membrane, a cap and a lead pin thereon with an internal lead extending from said internal electrode to said lead pin, said glass electrode being removably fitted into said glass electrode receiving recess with said lead pin in said lead pin receiving recess, the glass membrane projecting beyond the end of said central body; a protecting cap removably mounted on said central body around said glass electrode and having a lower open end projecting beyond the end of the glass membrane for protecting the glass electrode in the glass electrode receiving recess; a packing around said glass electrode in said glass electrode receiving recess and engaged by said protecting cap for being held in position in said recess; a second body mounted on said central body, a porous side wall removably mounted on said bodies and defining with said bodies an internal solution receiving space, an internal electrode removably mounted in said internal solution receiving space and having a lead and a lead pin extending out of the end of the combination electrode remote from said protecting cap, a thermistor removably mounted in said second body and having leads and lead pins extending out of the end of said combination electrode remote from said protecting cap, a further lead pin connected to said contact pin in said central body also extending out of the end of the combination electrode remote from said protecting cap, and a second protecting cap removably mounted around the outside of said second body.