Spacing compensating electrostatic voltmeter

In an electrostatic type voltmeter for measuring the potential on a surface, the voltmeter including:

• a probe;
• support means for supporting said probe in spaced relationship with said surface, said probe having a plurality of spacing element sites thereon for measuring a distance between each of said plurality of spacing elements sites and a corresponding area on said surface opposite of each said plurality of spacing element sites;
• a plurality of electrostatic element sites, intermixed and adjacent to said plurality of spacing element sites on said probe, for measuring a voltage between each of said plurality of spacing element sites and an area on said surface adjacent to said corresponding area opposite of each said plurality of spacing element sites;
• each of said plurality of electrostatic element sites includes:
• a sensor component for measuring a voltage by capacitive coupling;
• a movable shutter that selectively overlays the sensor component;
• and
• a shutter driver for opening and closing said movable shutter;
• and
• said shutter defines a plurality of windows movable between a first position where the sensor component is exposed and a second position where the sensor component is covered, the shutter being adjacent to the sensor component and means for compensating an output signal of said probe in response to the measurements received from said plurality of spacing element sites and said plurality of electrostatic element sites.