The last decade of research and development has led to tremendous increases in the complexity of electronic devices. It has also led to significant decreases in the size and power requirements of these devices. The combination of these has led to a vastly increased susceptibility potential of electronic products to electromagnetic interference (EMI). This potential has resulted in the requirement to develop small electromagnetic field sensors to assess the susceptibility of engineering prototypes to EMI. This paper presents an overview of the state-of-the-art technology in small electromagnetic field sensor systems, and provides an insight into ongoing research and new developments.