A Digital Electromagnetic Induction Measurement System Based on FPGA

Electromagnetic measurement has advanced rapidly in recent years because of its characteristics of non-contact and non-invasion nature. This paper presents an electromagnetic measurement system based on Field Programmable Gate Arrays (FPGA). The core of the system is a FPGA chip in which DDS, FIFO, digital demodulation module and MCU are embedded. The system consists of a flexible multi-frequency excitation source and a high-precision dual-channel voltage/current measurement unit. The sensing voltage and the excitation current can be measured synchronously to acquire the induction impedance. Digital demodulation technology under FPGA support is used to obtain the amplitude and phase information of the measured signal. Experimental work is undertaken to assess the feasibility of the system.