Abstract: During a measurement in KFM mode of the surface potential of a material (P), a detection point (1) is arranged above a surface (S) of the material. Two piezoelectric actuators (2, 5) are used to monitor a mean distance of the detection point relative to the surface of the material and a mechanical oscillation of said point. During the measurement, a control voltage is applied between control electrodes (2a, 2b) of the piezoelectric actuator (2) which is dedicated to the mechanical oscillation of the detection point (1), said control voltage not having an alternative component to an angular frequency of electrical energization of said detection point. A result of the KFM measurement is therefore separate from operating parameters such as a projection angle used to perform closed-loop control and a value of the angular frequency of electrical energization. The invention thus provides absolute measurements of surface potentials.

Abstract: During a measurement in KFM mode of the surface potential of a material (P), a detection point (1) is arranged above a surface (S) of the material. Two piezoelectric actuators (2, 5) are used to monitor a mean distance of the detection point relative to the surface of the material and a mechanical oscillation of said point. During the measurement, a control voltage is applied between control electrodes (2a, 2b) of the piezoelectric actuator (2) which is dedicated to the mechanical oscillation of the detection point (1), said control voltage not having an alternative component to an angular frequency of electrical energisation of said detection point. A result of the KFM measurement is therefore separate from operating parameters such as a projection angle used to perform closed-loop control and a value of the angular frequency of electrical energisation. The invention thus provides absolute measurements of surface potentials.