Cubic Gasboard-7500K-OAQ Ultrasonic Gas Flow Sensor

Overview

The Cubic Gasboard-7500K-OAQ is an ultrasonic transit-time gas flow sensor engineered for high-reliability, low-power, and maintenance-free measurement of volumetric gas flow in ambient and industrial environments. Unlike thermal mass or differential pressure-based sensors, the Gasboard-7500K-OAQ employs dual-path ultrasonic transducers operating in a time-of-flight configuration—measuring the differential propagation time of ultrasonic pulses traveling with and against the gas stream. This principle ensures inherent immunity to variations in gas composition, humidity, temperature-induced density shifts, and particulate loading—critical for stable performance in variable ambient conditions typical of environmental monitoring, combustion control, and indoor air quality (IAQ) systems. The sensor builds upon the field-proven Gasboard-7500 platform, incorporating enhanced electromagnetic compatibility (EMC) shielding, optimized signal conditioning circuitry, and extended thermal stability across its full operating range (−20 °C to +60 °C). Its compact form factor and TTL-level UART interface enable seamless integration into embedded OEM systems, portable analyzers, and distributed sensor networks without requiring external signal conditioning or recalibration.

Key Features

• Ultrasonic transit-time measurement principle—immune to humidity, CO₂, VOCs, and non-condensing aerosols
• Factory-trimmed zero offset compensation—no field zeroing required over lifetime
• High-speed dynamic response (≤0.3 s T₉₀) suitable for transient flow profiling and real-time feedback control
• Low power consumption (≤35 mA at 5 V), enabling battery-operated or energy-harvested deployments
• Robust EMC design compliant with EN 61000-4 series standards—validated for operation near variable-frequency drives, switching power supplies, and RF sources
• Compact footprint (120 × 30 × 22 mm) with integrated mounting flange and IP54-rated housing (optional gasket kit available)
• No moving parts or consumables—designed for >50,000 hours MTBF under continuous operation

Sample Compatibility & Compliance

The Gasboard-7500K-OAQ is validated for use with dry and humidified air, nitrogen, oxygen, argon, natural gas simulants (CH₄/N₂ blends), and medical-grade breathing gases. It is not intended for corrosive, abrasive, or condensing gas streams. The sensor meets China’s Metrology Certification (CMC) requirements per JJF 1071–2010 for flow instrumentation, carries CE marking under Directive 2014/30/EU (EMC) and 2014/35/EU (LVD), and conforms to IEC 61326-1:2013 for electromagnetic immunity in industrial environments. While not certified to ISO 5167 or AGA-9, its output is traceable to NIM (National Institute of Metrology, China) reference standards via factory calibration reports supplied with each unit. For GLP/GMP-regulated applications, raw UART data logs may be archived with timestamping and checksum verification for audit readiness.

Software & Data Management

The sensor communicates via asynchronous UART (TTL 5 V logic, 8N1, configurable baud rates from 9600 to 115200 bps). A standardized ASCII protocol delivers real-time flow rate (L/min), internal temperature (°C), and diagnostic status flags—including transducer health, signal-to-noise ratio (SNR), and voltage rail monitoring. Cubic provides open-source firmware libraries for ARM Cortex-M, ESP32, and Raspberry Pi platforms, along with Python SDKs supporting Pandas-based batch analysis and CSV export. All firmware updates are signed and delivered over secure UART handshake. No proprietary drivers or cloud dependencies are required—enabling fully offline, deterministic data acquisition compatible with IEC 62443-3-3 Level 1 security profiles.

Applications

• Continuous emission monitoring systems (CEMS) for stack gas flow profiling
• Oxygen concentrator and ventilator airflow feedback loops
• Smart HVAC demand-controlled ventilation (DCV) using CO₂-correlated air exchange rate estimation
• Portable IAQ monitors integrating PM2.5, TVOC, and CO₂ with volumetric dilution correction
• Lab-scale bioreactor sparging control and exhaust gas flow balancing
• Calibration transfer standards for field-deployable gas analyzers requiring traceable flow reference

FAQ

Does the Gasboard-7500K-OAQ require periodic recalibration?
No. It is factory-calibrated against NIM-traceable flow benches and features drift-compensated transducer electronics. Under normal operating conditions (non-condensing, particle-free gas), recalibration is not recommended within 5 years.
Can it measure bidirectional flow?
No. It is unidirectional and must be installed with arrow-aligned gas flow direction. Reverse flow generates invalid or saturated readings.
Is the UART interface compatible with RS-232 or RS-485 systems?
Not natively. A level-shifting circuit (e.g., MAX3232 or SP3485) is required for RS-232/RS-485 interoperability.
What is the minimum detectable flow rate with usable accuracy?
The lower limit of reliable measurement is 0.5 L/min (±0.2 L/min absolute error dominates below this point); for sub-LPM applications, consider the Gasboard-7500S variant.
Does it support Modbus RTU or CAN bus protocols?
No. Only UART TTL is supported. Protocol conversion gateways may be deployed externally if needed.