Model 518B is an embedded accelerometer permitting simultaneous vibration monitoring and shock measurements. 518B features an annular shear ceramic crystal which exhibits excellent output stability over time. The accelerometer incorporates an internal circuit in a three-wire signal system which powered by voltage excitation and output with voltage signal. Excellent electrical design enables the low current consumption that ideal for wireless device with battery power supply. Signal ground is connected to the outer case of the unit, Isolated mounting washer is available. Polarity inversion protection for the amplify circuit is inherent in the circuit design. The stainless-steel construction provides a lightweight hermetic housing. Three wire lead cable are convenient for structure assembly and electrical connection. Compact columnar configuration is fit with most of the impact testing device. The 518B provides wide frequency response, which is ideal for dynamic vibration and shock measurement especially for lightweight structures.