AIDE SWH3A NDIR Gas Sensor Module

Overview

The AIDE SWH3A NDIR Gas Sensor Module is a high-precision, digitally integrated infrared sensing platform engineered for reliable, long-term quantitative analysis of trace and percent-level gases in environmental, industrial, and pharmaceutical applications. Based on non-dispersive infrared (NDIR) spectroscopy—complemented by selective VIS and NIR absorption bands—the module delivers stable, drift-compensated measurements without moving parts or consumables. Its core architecture leverages dual-beam optical path design and thermally stabilized detectors to minimize thermal noise and enhance signal-to-noise ratio. The SWH3A is optimized for single-gas detection (e.g., CO, CO₂, NO, SO₂, CH₄, N₂O, SF₆, CF₄, C₂H₂, SO₂F₂), with configurable multi-channel variants supporting up to three simultaneous analytes in a single-layer configuration and six in dual-layer modular integration. Designed for seamless OEM integration, it operates across ambient temperature ranges (0–45 °C) with full internal temperature and barometric pressure compensation—ensuring metrological consistency under variable field conditions.

Key Features

• True NDIR-based detection with spectral selectivity for CO, CO₂, NO, SO₂, CH₄, N₂O, SF₆, CF₄, C₂H₂, SO₂F₂, and other IR-active gases
• 16-bit analog-to-digital conversion enabling sub-ppm resolution and high dynamic range (0–20 ppm to 0–100% vol)
• Ultra-fast response: T90 < 4 s at 60 L/h flow rate; T90 < 3 s at 180 L/h—validated per ISO 12039 and IEC 60079-29-1 test protocols
• Integrated automatic zero and span compensation algorithms—reducing calibration frequency while maintaining ±1% F.S. accuracy over time
• Dual-layer modular option with independent sampling units for parallel gas streams or redundant measurement channels
• Low-power 5 V DC operation (8 W typical, 15 W dual-layer), suitable for battery-powered portable analyzers and fixed-site controllers
• Robust mechanical housing with IP54-rated enclosure compatibility and EMI-hardened signal conditioning circuitry

Sample Compatibility & Compliance

The SWH3A is validated for use with dry, non-corrosive gas matrices—including ambient air, stack emissions, cleanroom atmospheres, and process gas streams. It meets functional requirements for continuous emission monitoring (CEM) and indoor air quality (IAQ) applications as defined in ISO 16000-23 (indoor air—determination of carbon dioxide), ASTM D6245 (CO₂ in ambient air), and EN 14625 (portable CO detectors). While not intrinsically safe certified out-of-box, the module supports integration into ATEX/IECEx-certified enclosures when paired with appropriate barrier circuits. Its analog and digital outputs comply with IEC 61000-6-2/6-3 for electromagnetic immunity and emission. For regulated environments (e.g., pharmaceutical cleanrooms or EPA reference methods), the sensor’s traceable calibration protocol and audit-ready output logs support GLP/GMP-aligned data integrity practices.

Software & Data Management

The SWH3A interfaces natively via RS-232, RS-485, and USB with host systems running Windows, Linux, or embedded RTOS platforms. Included PC software provides real-time waveform visualization, spectral baseline diagnostics, and automated calibration logging—including timestamped zero/span events, temperature/pressure metadata, and drift trend reporting. All digital outputs embed CRC-16 error checking and support Modbus RTU protocol for SCADA integration. Analog outputs (0–1 V, 4–20 mA) are factory-trimmed to NIST-traceable standards and retain linearity within ±0.1% over full scale. Optional firmware upgrades enable remote firmware updates, user-defined alarm thresholds, and CSV-exportable time-series datasets compliant with FDA 21 CFR Part 11 requirements when deployed with validated electronic signature modules.

Applications

• Ambient air quality monitoring networks (AQMS) measuring urban CO, CO₂, and NOₓ levels
• Pharmaceutical facility HVAC control for CO₂-based occupancy sensing and sterile room ventilation verification
• Industrial safety systems for confined-space entry (CO, O₂, CH₄) and fumigation residue detection (SO₂F₂, SF₆)
• Biogas upgrading plants requiring real-time CH₄/CO₂ ratio feedback for membrane separation optimization
• Research-grade greenhouse gas flux chambers and eddy covariance systems
• OEM integration into portable breath analyzers (N₂O, CO), refrigerant leak detectors (CF₄, CHF₃), and combustion efficiency analyzers

FAQ

What gases can the SWH3A measure simultaneously?
The standard single-layer SWH3A supports up to three gases concurrently (e.g., CO + CO₂ + NO); dual-layer configurations extend this to six gases using physically isolated optical paths.
Does the module require periodic manual calibration?
No—automatic zero tracking and pressure/temperature compensation reduce routine calibration to once every 6–12 months under stable operating conditions, per ISO 12039 maintenance guidelines.
Is the SWH3A compatible with existing PLC or DCS systems?
Yes—RS-485 Modbus RTU and 4–20 mA analog outputs ensure direct integration with Allen-Bradley, Siemens S7, and Honeywell Experion DCS platforms.
Can the SWH3A be used in high-humidity environments?
It is rated for operation up to 90% RH non-condensing; optional hydrophobic inlet filters and heated sample lines are recommended for sustained exposure above 70% RH.
What documentation is provided for regulatory validation?
ONUEE supplies a Factory Calibration Certificate (traceable to PTB/NIST), EMC test reports, RoHS/REACH declarations, and a Design Qualification Summary aligned with ICH Q9 principles for critical parameter justification.