combination electrode

https://doi.org/10.1351/goldbook.C01184
An ion-selective electrode and an external reference electrode combined in a single unit, thereby avoiding the need for a separate external reference electrode.
Source:
PAC, 1994, 66, 2527. (Recommendations for nomenclature of ionselective electrodes (IUPAC Recommendations 1994)) on page 2528 [Terms] [Paper]