An electromagnetic flowmeter has a flowtube configured to carry a conductive fluid. The flowtube has wall made of a conductive material. The wall has an inner surface surrounding a fluid flow path for the fluid. A non-conductive liner is positioned to electrically insulate the flowtube wall from the fluid. The flowtube and non-conductive liner define an electrode mounting hole. An electrode extends through the electrode mounting hole. The electrode and the non-conductive liner form a fluidic seal between the electrode mounting hole and the fluid flow path. At least a portion of the electrode is arranged in fluid communication with the flowtube within the electrode mounting hole. A short circuit detector can detect failure of the seal when conductive fluid that has leaked past the seal creates a short circuit as a result of the fluid communication between the flowtube and the electrode mounting hole.