Signal Detection Methods for Magnetostrictive Sensors

Magnetostrictive sensors offer many attractive features. Their strain sensitivity is significantly higher than that of strain gages. They are simple, rugged and inexpensive. Signal conditioning requirements for the magnetostrictive sensors are determined by the selection of a signal detection method. This article experimentally investigates different signal detection methods for single branch magnetostrictive sensors with conventional excitation and detection coils. Monitoring excitation voltage while holding excitation current constant, or monitoring excitation current while holding excitation voltage constant produces much better output signal compared to the detection voltage. Furthermore, this study suggest that the detection coil is not really needed, leading to a novel single branch magnetostrictive sensor without a detection coil.