Contact potential difference (CPD) was measured by macroscopic Kelvin probe
instrument and scanning Kelvin probe microscope on Al, Ni and Pt on ITO
substrates at ambient conditions. CPD values measured by scanning Kelvin
probe microscope and macroscopic Kelvin probe are close within the error of
about 10–30% for large studied objects, whereas scanning Kelvin probe
microscope signal decreases, when the object size becomes smaller than 1.4
μm. CPD and electric field signals measured using many-pass technique
allowed us to estimate the influence of electrostatic field disturbance,
especially, in the case of small objects.