Sensitive acceleration sensor using amorphous wire SI element combined with CMOS IC multivibrator for environmental sensing

A highly sensitive and quick response acceleration sensor has been constructed using the stress-impedance (SI) element of 20 /spl mu/m diameter CoSiB amorphous wires combined with a CMOS IC multivibrator. The resolution of the acceleration sensor is 10/sup -3/ Gal(=0.01 m/s/sup 2/) for repetitive vibration and 0.1 Gal for nonrepetitive motion. The high sensitivity is based on the ultrahigh values of the gauge factor of about 4000 in the CoSiB amorphous wire SI element. The power consumption is about 6 mW due to the pulse magnetization circuitry. Basic properties of the acceleration sensor and application to the sensing of road bridge seismovibration due to car passing are presented.