In the work, micro-probe is attached to floating plate of the capacitive sensors under microscopic environment. Then we connect pad of micro capacitive sensors to pad of PCB by press welder. The experimental set-up is placed on a vibration isolator with air springs. A macro–micro calibration stage is constructed, in which large range coarse positioning is realized with a micrometer screw mechanism and nanometer positioning is realized with piezoelectric nano-positioning stage P-753 which has a travel of 12 m, a closed-loop resolution of 0.1 nm and a full-range repeatability of ±1 nm. The experimental set-up is configured, as is shown in Fig. 7.