29
Q
Please explain the measurement principles for the electrostatic
potential sensor EP Sensor.
A
Detecting
circuit
Detecting
electrode
EP Sensor
Induction
charge
Ground
Charge (when the charge is positive)
Charged body
Field
The electrostatic potential sensor EP Sensor uses the electrostatic induction phenomenon that
arises between the charged body and detection electrodes. The electric field from the charged body
generates an induction charge in the detection electrode surface. This induction charge is then
calculated and displayed as the potential of the charged body.
A high-speed tuning fork shutter is incorporated in the front of an actual detecting electrode. An
alternating current signal proportional to the charge is obtained, depending on the amount of
shutter opening and closing, and that signal is used to measure the potential of the charged body.
Basic Principles
Charge Q (induction charge) is proportional to the voltage V (charge voltage).
The EP Sensor uses the tuning fork shutter method to perform measurement.
Tuning fork shutter
opens and closes.