Cubic Gasboard-7500K Ultrasonic Oxygen Sensor

Overview

The Cubic Gasboard-7500K is an industrial-grade ultrasonic oxygen sensor engineered for simultaneous, real-time measurement of oxygen concentration and volumetric flow rate in binary gas mixtures—primarily air/O₂ or nitrogen/O₂ systems. Unlike electrochemical or paramagnetic sensors, the Gasboard-7500K employs time-of-flight (TOF) ultrasonic principle: two opposing transducers emit and receive high-frequency acoustic pulses across a defined measurement path; differential transit times between upstream and downstream propagation are directly correlated to both gas composition (via sound velocity dependence on molecular weight and heat capacity ratio) and bulk flow velocity (via Doppler shift and transit-time difference). This dual-parameter output eliminates the need for separate flow meters or secondary concentration analyzers in compact medical and home-care oxygen generation systems. Designed as an enhanced iteration of the proven Gasboard-7500 platform, the 7500K integrates reinforced electromagnetic compatibility (EMC) shielding, extended thermal stability architecture, and embedded full-range temperature compensation algorithms—ensuring metrological consistency across ambient operating conditions without user intervention.

Key Features

• Dual-output capability: Simultaneous analog-equivalent digital reporting of O₂ concentration (% vol) and volumetric flow (L/min) via single UART interface
• Zero-drift design: Factory-trimmed calibration with lifetime stability—no scheduled recalibration required under specified operating conditions
• Integrated thermal compensation: On-board temperature sensor and adaptive algorithm correct for sound velocity drift across 10–45°C operational envelope
• Robust EMC performance: Meets IEC 61000-4-2/3/4/6 standards for electrostatic discharge, radiated RF immunity, fast transient bursts, and conducted disturbances
• Low-power architecture: Average current draw <35 mA at 5 V enables direct integration into battery-backed or energy-constrained medical devices
• Compact form factor: 120 × 22 × 13.6 mm footprint optimized for OEM embedding in PSA-based oxygen concentrators, hyperbaric chambers, and portable respiratory support units

Sample Compatibility & Compliance

The Gasboard-7500K is validated for use in dry, non-corrosive binary gas streams where the second component is inert (e.g., N₂) or low-molecular-weight (e.g., Ar). It is not intended for humidified, particulate-laden, or chemically aggressive gas matrices without upstream conditioning (e.g., desiccant filtration, particulate traps). The sensor complies with mandatory regulatory frameworks for medical and environmental instrumentation in global markets: China Metrology Certification (CMC) per JJG 537–2018, CE marking under Directive 2014/30/EU (EMC), and conformity to RoHS 2011/65/EU. While not a standalone medical device, it satisfies essential requirements for incorporation into Class IIa oxygen therapy equipment per ISO 13485–2016 quality management systems and supports traceability under FDA 21 CFR Part 820 when deployed in U.S.-registered manufacturing environments.

Software & Data Management

Data output is delivered via asynchronous UART (TTL-level, 5 V logic) at configurable baud rates (default: 9600 bps, 8N1). The protocol supports ASCII command-response framing for readout of live concentration, flow, internal temperature, and diagnostic status registers (e.g., signal-to-noise ratio, transducer health flag). No proprietary drivers or cloud dependencies are required; raw data streams integrate natively with common microcontroller platforms (ARM Cortex-M, ESP32, PIC32) and industrial PLCs via standard serial libraries. Firmware updates—though rarely needed due to hardware-stable calibration—are supported over UART using CRC-secured packet transmission. Audit-ready logging is achievable through host-side timestamping and buffering, satisfying GLP-aligned record retention practices where long-term trend analysis of oxygen delivery performance is mandated.

Applications

• Pressure Swing Adsorption (PSA) oxygen concentrators: Real-time feedback control of sieve bed cycling and purity verification
• Medical oxygen generators and transport ventilators: Closed-loop O₂ dose modulation and alarm triggering at deviation thresholds
• Hyperbaric oxygen therapy (HBOT) chambers: Continuous monitoring of inlet gas composition and mass flow during pressurization cycles
• Lab-scale gas blending systems: Precise stoichiometric control in controlled-atmosphere incubators or catalytic reaction studies
• Industrial inerting systems: Verification of O₂ depletion levels in nitrogen-purged enclosures prior to solvent handling

FAQ

Does the Gasboard-7500K require periodic recalibration?

No. It features factory-established calibration with lifetime zero-drift compensation; no field recalibration is necessary under normal operating conditions.
Can it measure oxygen in humidified gas streams?

Not directly. Condensation or sustained >95% RH exposure may impair acoustic coupling; use with inline desiccants or heated sample lines is recommended.
Is the UART interface compatible with 3.3 V logic microcontrollers?

The default output is 5 V TTL; level-shifting circuitry is required for direct connection to 3.3 V UART peripherals.
What is the maximum allowable pressure for continuous operation?

The sensor is rated for ambient pressure operation only (±10 kPa); pressure-compensated variants are available upon OEM request.
How is long-term stability verified during production?

Each unit undergoes 168-hour accelerated life testing at 45°C and 85% RH, followed by concentration/flow accuracy validation against NIST-traceable reference standards.