Cryogen adaptive and integrated differential pressure sensor for level sensing based on an optical Fabry-Perot...

Area of Science:

• Materials Science
• Mechanical Engineering
• Sensor Technology

Background:

• Accurate level measurement of cryogenic fluids is crucial for various industrial and scientific applications.
• Traditional sensors often face challenges in extreme low-temperature environments.
• Micro-electromechanical systems (MEMS) offer potential for miniaturized and robust sensor designs.

Purpose of the Study:

• To develop and evaluate a novel cryogen-adaptive sensor for precise cryogenic fluid level measurement.
• To demonstrate the sensor's performance characteristics, including linearity, accuracy, and temperature stability.
• To explore the sensor's applicability for measuring various cryogenic liquids.

Main Methods:

• Fabrication of a MEMS-based sensor integrating an optical fiber, glass ferrule, and Fabry-Perot (FP) chip.
• Utilization of a low coherent interference system to convert liquid level to absolute phase.
• Conducting liquid nitrogen level measurement experiments to validate sensor performance.

Main Results:

• The sensor exhibits a monotonic linear response with a coefficient of determination (R²) greater than 0.998.
• The measurement error in liquid nitrogen was found to be less than ±5 mm.
• The sensor demonstrated excellent cryogenic temperature performance, operating effectively between -260°C and -100°C.

Conclusions:

• The developed MEMS sensor is highly effective for cryogenic fluid level measurement.
• The sensor's accuracy, linearity, and wide operating temperature range make it suitable for diverse cryogenic applications.
• This technology shows significant potential for advancing level sensing in challenging cryogenic environments.