Fluxgate-Based Displacement Sensor Design

This report presents a design for a double-rod core fluxgate sensor. The design features two identical conventional fluxgate sensors with their excitation coils connected in an anti-parallel configuration while the pick-up coils are interconnected in the same orientation. The purpose of the sensor is to detect displacement in general machining machines. The sensor consists of an excitation coil and a pick-up coil wrapped around a core made of the high permeability amorphous alloy Metglas 2714A ribbon, which has low hysteresis and a highly saturated magnetic field. The cores are bar-shaped and precision-cut with double core layers to increase flux density. The sensor’s high sensitivity of 206 mV/mT and low noise of 0.4 nT/sqrtHz@1 Hz were experimentally determined. In distance measurements, the device has a responsivity of 2.18 V/mm with an initial mounting position to the target of 3 mm. The results indicate that the proposed design is suitable for displacement applications.