A Comparability Study of a Wireless Electret Accelerometer to a Traditional Piezoelectric Accelerometer

Traditional piezoelectric accelerometers used for machine condition monitoring are expensive and represent a capital risk when placed in the harsh environment of a cutting process. Additionally, these components require signal conditioning hardware and are sampled on a PC via an independent data acquisition interface (DAQ card). The goal of the research discussed herein is to test an industrial-friendly electret-based accelerometer that can perform tasks similar to a traditional piezoelectric accelerometer. The sensor will be adapted to utilize Bluetooth wireless data capabilities, further enhancing the sensors industrial practicality. The output of this electret-based sensor will be compared to the output of a traditional piezoelectric accelerometer and accompanying DAQ. More specifically, the study will focus on the effects of elevated temperature on the sensor. To achieve this, a comparison of both the electret and piezoelectric accelerometer response spectra will be observed over a range of 21°C to 77°C. To further validate the sensor, turning data is collected wirelessly from the sensor and compared to the output of the traditional piezoelectric sensor. Finally, the performance of the sensor for monitoring a tool’s condition during turning is evaluated and presented. The generated trend is contrasted to the comparable trend developed from the piezoelectric-based accelerometer.