FIELD: electricity.
SUBSTANCE: measurement is carried out by means of contact of a metering electrode (3) with a surface of an investigated sample (2) and subsequent opening of an electric contact. An electrode (3) after opening of a contact with a sample (2) is moved with the help of an electromechanical facility of displacement (4) in direction from the surface of the sample (2). In process of measurements, screening of the metering electrode is provided with the help of an electroconductive screen (7), connected to a common output of the power supply unit. Voltage fixed on the metering electrode (3), is amplified with the help of an operational amplifier (8). An inverting input of an amplifier (8) is connected to a metering electrode (3). A non-inverting input of an amplifier (8) is connected to a common output of a power supply unit. An amplified signal from an output of the amplifier (8) is supplied to the investigated sample (2) via the electroconductive body (1), the end part of which forms an electric contact with the sample (2). Supply of the amplifier (8) is carried out with the help of a power supply unit comprising an AC voltage converter (5) and a DC voltage converter (6). With the help of a voltage recorder (9), variance of voltage on the sample (2) is measured depending on distance between opposite surfaces of the sample (2) and the electrode (3). The measured dependence is used as an electric characteristic of contact difference of potentials for a selected pair of materials of the sample (2) and the electrode (3).
EFFECT: increased accuracy of detecting contact difference of potentials and provision of automation of measurements process.
14 cl, 3 dwg
