Pulsed eddy current testing（PECT） has been widely used for ferromagnetic pipelines detection.However

in case of non-ferromagnetic pipelines with small diameters

which results in itself can not focus electromagnetic fields like ferromagnetic materials

there are still problems to be solved.A type of sensor with a racetrack-shaped driver coil is proposed

which can effectively reduce the electromagnetic energy dissipation and expand effective coverage area of sensor.Firstly

effective coverage area of racetrack-shaped and cylindrical exciting coils in small-diameter pipe is analyzed and compared.Then

based on analytical model for 3D pipe to calculate coil coefficient of racetrack-shaped coil

build analytical model for racetrack-shaped sensor.Based on the analytical model

the performance of the racetrack-type sensor on the thickness measurement for a stainless-steel pipe are studied and experimentally verified.The results show that the racetrack-type pulsed eddy current sensor is more suitable for thickness measurement for stainless-steel pipes with small diameters.