Cryogenic Level Gauges

High-precision sensors for real-time propellant monitoring. We design capacitive level gauges for LH2, LOX, and LCH4 tanks, ensuring accurate mass measurement during ground loading and flight.

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Precision monitoring for mission success

Knowing the exact quantity of propellant on board is critical for launch success. Air Liquide’s cryogenic level gauges provide continuous, high-accuracy measurement of liquid levels inside fuel tanks (LH2, LOX, LCH4). Designed to operate under extreme thermal and mechanical stress, they are essential for validating loaded mass before lift-off and monitoring propellant consumption during flight.

Our sensors use electricity to instantly tell the difference between liquid and gas. This ensures a robust measurement where the electrical capacity is linearly proportional to the liquid level, providing reliable data without moving parts.

Technical Versatility:

  • Fluids: Compatible with liquid hydrogen (LH2), oxygen (LOX), and methane (LCH4).
  • Sizing: Available in various lengths to suit different tank geometries, including short sensors (200 mm) and long sensors (464 mm) for broader range monitoring.

Critical Functions: Ground & Flight

These gauges serve dual purposes in the launcher lifecycle:

  • Ground Operations: They enable to manage chill-down and filling operations and ensure the launcher is loaded with the precise required propellant mass, preventing overfilling or underfilling before liftoff.
  • In-Flight: They monitor tank draining in real-time, providing critical data used to implement engine shut-down criteria, protecting turbopumps from running dry.

Adaptability for New Space

As the launcher market evolves towards reusable and methane-based vehicles, Air Liquide continues to innovate. Our level gauges can be integrated into New Space launchers.

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Our Launchers cryogenic equipment & technologies

  • Insulated & equipped cryogenic tanks
    Advanced insulated cryogenic tanks for space launchers (LH2, LOX, LCH4). Design authority for Ariane 6 and 800+ flight models delivered for Ariane overall.
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  • Liquid Helium Sub System (SSHeL)
    High-performance liquid helium (LHe) storage for launcher pressurization. Aluminum double-wall vacuum insulated technology with 120+ flight models delivered.
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  • Propellant Management Devices (PMD)
    Advanced propellant management devices for space launchers (LH2, LOX, LCH4). Anti-vortex & anti-sloshing systems qualified for Ariane 1-6.
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  • Cryogenic Insulation Systems
    Advanced thermal protection for space launchers (LH2, LOX, LCH4). Sprayed foam & MLI solutions qualified for Ariane 6.
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  • Cryogenic lines
    High-performance cryogenic lines for space launchers (LH2, LOX, LHe). Custom aluminum or stainless steel designs with 140+ references for Ariane 6.
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