Simultaneous telemetry of temperature and vibration by laser dispersion spectroscopy

Area of Science:

• Optical sensing
• Spectroscopy
• Industrial instrumentation

Background:

• Temperature and mechanical vibration are critical industrial parameters, often measured independently.
• Existing methods lack simultaneous measurement capabilities for coupled thermal-vibration phenomena.

Purpose of the Study:

• To develop a novel method for simultaneous telemetry of temperature and vibration parameters.
• To enhance measurement accuracy and signal-to-noise ratio in coupled environments.

Main Methods:

• Utilizing laser dispersion spectroscopy at two central wavelengths.
• Extracting temperature from the peak-to-peak ratio of absorption spectra.
• Deriving vibration amplitude and frequency from time-varying spectral baselines.

Main Results:

• Developed a telemetry sensor evaluated on a thermal vibration coupled platform.
• Achieved temperature readings in close agreement with a reference thermocouple.
• Demonstrated a signal-to-noise ratio at least 18 dB higher than classical direct laser absorption spectroscopy (DLAS).
• Vibration frequencies matched commercial laser Doppler vibrometer (LDV) outputs.
• Obtained vibration amplitude sensitivity of 3.64 micrometers (Allan variance).

Conclusions:

• The proposed laser dispersion spectroscopy method enables accurate, simultaneous measurement of temperature and vibration.
• This novel approach significantly improves upon existing techniques in terms of signal-to-noise ratio and accuracy.
• The developed telemetry sensor is effective for monitoring coupled thermal-vibration conditions in industrial applications.