A displacement sensor with controlled measuring force and its error analysis and precision verification are discussed in
this paper. The displacement sensor consists of an electric induction transducer with high resolution and a voice coil
motor (VCM). The measuring principles, structure, method enlarging measuring range, signal process of the sensor are
discussed. The main error sources such as parallelism error and incline of framework by unequal length of leaf springs,
rigidity of measuring rods, shape error of stylus, friction between iron core and other parts, damping of leaf springs,
variation of voltage, linearity of induction transducer, resolution and stability are analyzed. A measuring system for
surface topography with large measuring range is constructed based on the displacement sensor and 2D moving platform.
Measuring precision and stability of the measuring system is verified. Measuring force of the sensor in measurement
process of surface topography can be controlled at μN level and hardly changes. It has been used in measurement of
bearing ball, bullet mark, etc. It has measuring range up to 2mm and precision of nm level.