A rugged, high precision capacitance diaphragm low pressure gauge for cryogenic use

Area of Science:

• Atmospheric Chemistry
• Planetary Science
• Spectroscopy

Background:

• Precise gas pressure measurement is crucial for laboratory studies in atmospheric chemistry.
• Accurate data is needed for analyzing infrared absorption intensities and line profiles of volatile compounds.

Purpose of the Study:

• To design, build, and test a prototype precision capacitive pressure gauge for cryogenic applications.
• To enable accurate gas pressure measurements in the 10(-3) to few mbars range for atmospheric research.

Main Methods:

• Developed a rugged, capacitive pressure gauge using corrosion-resistant materials.
• Employed a differential measurement scheme with a capacitance-to-digital converter chip.
• Tested the prototype gauge in a cryogenic environment down to 77 K.

Main Results:

• Achieved a precision better than 1% in the 0.2-40 mbar pressure range.
• Demonstrated a resolution of 2 × 10(-3) mbar.
• The gauge is tunable for adjusted precision and resolution.

Conclusions:

• The developed capacitive pressure gauge meets the requirements for precise gas pressure measurements in cryogenic atmospheric research.
• The design offers a robust and accurate alternative to traditional high-precision capacitive bridges.