Second Generation Data-Logging System for Long-Duration Field Measurement of Vibration Exposure and Grip Force

Millions of United States workers are exposed to vibration at their job, whether it is from a power tool that causes hand and arm vibration or from heavy machinery. These vibrations are known to result in physical disorders such as Hand-Arm Vibration Syndrome, which can be debilitating to the point where workers can no longer do their job effectively. Research groups have taken an interest in finding what vibration characteristics are most harmful and choose to record vibration information using data-logging devices. Often, many devices, whether they are commercial or custom-built devices, use frequency weightings and full day estimations to measure vibration exposure, in which data can be lost due to pre-software filtering and short measurement durations. Using surface mount components on a custom-designed printed circuit board, a portable device that captured full vibration waveforms over multiple force and acceleration channels was created. In this device, signals are anti-alias filtered, sampled, converted, and stored to a solid state memory device over the course of an entire workday (i.e., greater than or equal to 8 hours). The device created in this thesis has met specifications for resolution of force and accelerations channels that are 10- and 14-bits, respectively. Sampling rate specifications were also met, with force channels being sampled at 908 Hz and acceleration channels sampled at 5000 Hz each. A final robust dynamic range of 1 to 1000 m/s2 peak-to-peak was achieved for the acceleration channels and the device allowed for data capture of raw signals for over 9 hours