Abstract
The disturbance of electric field in the vicinity of the test electrode by the Luggin-Haber capillary was studied mathematically and empirically with the current interrupter. The equipotential line near the capillary tip was predicted, and considerable deformation was observed over about one third of the diameter of the capillary. The capillary located close to the surface of the test electrode disturbed the uniform current distribution, and the build-up curve of the oscilloscope trace was deformed. Its critical distance was about twice the diameter of the capillary.
