Laser Calorimetry Spectroscopy for ppm-level Dissolved Gas Detection and Analysis

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Physical Chemistry

Background:

• Conventional methods for dissolved gas detection require gas extraction and complex analysis.
• Existing techniques often lack the sensitivity and specificity needed for trace gas analysis in liquids.
• Accurate monitoring of dissolved gases is crucial in applications like transformer oil diagnostics.

Purpose of the Study:

• To introduce a novel technique, laser calorimetry spectroscopy (LCS), for sensitive dissolved gas detection.
• To demonstrate the capability of LCS for direct measurement of gases within liquids.
• To validate LCS for detecting specific dissolved gases, such as acetylene, in industrial fluids.

Main Methods:

• Laser calorimetry spectroscopy (LCS) combines laser absorption spectroscopy and calorimetry.
• The technique involves irradiating the liquid with a specific laser wavelength where the target gas absorbs.
• Temperature changes caused by the gas's absorbance are precisely measured to determine concentration.

Main Results:

• LCS enables direct detection of dissolved gases in liquids without prior extraction.
• The technique achieves parts-per-million (ppm) level sensitivity for dissolved gases.
• Dissolved acetylene in transformer oil was successfully detected at a 3021 nm mid-infrared wavelength.

Conclusions:

• Laser calorimetry spectroscopy (LCS) offers a sensitive and direct method for dissolved gas analysis.
• LCS eliminates the need for cumbersome gas extraction, simplifying the detection process.
• This technique holds significant potential for real-time monitoring and diagnostics in various industrial applications.