PURPOSE: To obtain a surface electrometer which can easily be replaced and has high detection precision, by constituting this surface electrometer by arranging a measurement electrode, intermittent breaking method, driving method for the intermittent breaking method, and output detection circuit for the measurement electro electrode in one enclosure.
CONSTITUTION: Surface electrometer M is fitted fixed-distance away from the drum-A surface of a surface to be measured. When sensor motor 52 is driven to turn cylindrical chopper 53, charge on the drum-A surface induces an alternating- current voltage across measurement electrode 55 through potential measurement window 55. This alternating-current voltage is amplified by pre-amplifier printed board 56. Further, light from light emitting diode 54 is detected by photo transistor 57 through light penetration window 60 and then extracted as a synchronizing signal. In this way, the surface electrometer is constituted in one enclosure, its replacement and distance setting from the measued surface are simplified and a surface potential can accurately be detected.
SUZUKI KOUJI
YOKOMIZO YOSHIKAZU
