Abstract
An innovative concept of noninvasive sensor device has been proposed and successfully demonstrated, which makes direction detections and intensity measurements for electric fields be drastically simplified and agile. Its primal feature is a unique geometry, with the simplicity of Columbus’ egg, where an ammeter and optical readout are internally contained in virtual-shorted parallel plates. While its electromagnetic principle for accurate sensing has been confirmed, its function to promptly image directions and distributions of electric fields has been demonstrated combining its aerial scan with a bulb-shuttered photographic camera.