The eddy current sensor is employed to detect suspension gap in maglev train

and input-output characteristic of eddy current sensor is serious nonlinear when the gap range of 0

20 mm

so the sensor should be calibrated

and sensor works in harsh environment and thus it is vulnerable and inspection and maintenance is needed sure. A gap sensor test system is designed to monitor the sensor characteristic and calibrate the nonlinear error. The main control unit of this system is designed with FPGA and the man-machine interface is compiled by Lab VIEW

fast test and online calibration of output characteristic of maglev train gap sensor are realized. It has many advantages such as simple hardware structure and friendly man-machine interface

. The experimental results show that the system can monitor the original characteristic of the sensor conveniently

output linearity of sensor corrected by this system is good

and it can meet the requirement of suspension control system perfectly.