HUANKONG GHK-4000 Portable NDIR Carbon Dioxide Analyzer

Overview

The HUANKONG GHK-4000 Portable NDIR Carbon Dioxide Analyzer is a field-deployable, multi-gas measurement instrument engineered for quantitative analysis of carbon dioxide and other infrared-active gases in ambient air and industrial exhaust streams. It operates on the principle of non-dispersive infrared (NDIR) absorption spectroscopy—where gas-specific absorption bands in the mid-infrared region (e.g., CO₂ at 4.26 µm) are measured using thermopile or pyroelectric detectors with optical bandpass filters. This method delivers high selectivity, long-term stability, and minimal cross-sensitivity to common interferents such as water vapor and methane—when properly filtered and compensated. Designed for regulatory-grade field use, the GHK-4000 meets the metrological requirements defined in JJG 635–2011 (Calibration Specification for Infrared CO and CO₂ Gas Analyzers) and supports compliance-driven applications including occupational exposure monitoring per OSHA PELs and ACGIH TLVs, as well as stack testing under HJ/T 44–1999.

Key Features

• High-selectivity NDIR sensing module with imported optical components, optimized for CO₂ detection at 4.26 µm with temperature and pressure compensation
• Modular external sensor chamber design enabling rapid, tool-free replacement of gas-specific optical cells without recalibration
• Integrated high-efficiency diaphragm sampling pump with >25 kPa vacuum capability—ensuring stable draw-through flow across variable duct pressures and leak scenarios
• Electronic mass flow meter with real-time closed-loop feedback control, maintaining constant sample flow (±1% accuracy) independent of pipeline backpressure or ambient barometric shifts
• Rechargeable lithium-ion battery pack rated for ≥8 hours of continuous operation under typical sampling conditions (1 L/min flow, 10 s interval logging)
• Dual-threshold audible (85 dB) and visual (dual-color LED) alarm system with user-defined upper/lower limits for CO₂ and co-measured gases
• On-device calculation of time-weighted average (TWA), short-term exposure limit (STEL), peak concentration, and rolling 1-minute average—aligned with ISO 8573-1 and EN 689 frameworks
• Multi-unit display support: % volume, ppm, and mg/m³—with automatic conversion based on molecular weight, temperature, and pressure inputs
• Optional Bluetooth-enabled thermal printer for on-site report generation, supporting customizable templates compliant with internal QA documentation protocols

Sample Compatibility & Compliance

The GHK-4000 is validated for direct sampling of undiluted ambient air, flue gas (with optional heated probe and particulate filter), and confined-space headspace. Its NDIR architecture inherently accommodates mixed-gas matrices containing CO₂, CH₄, C₃H₈, C₂H₄, C₂H₅OH, ethylene oxide, methyl bromide, and SF₆—each selectable via interchangeable optical modules. The instrument conforms to Chinese national standards GB 12358–2006 (General Technical Requirements for Gas Detection Alarm Instruments in Workplace Environments) and JJG 635–2011 (Verification Regulation for Infrared CO/CO₂ Analyzers). While not certified to IECEx or ATEX for Zone 0/1 deployment, it is suitable for Class I, Division 2 environments when operated with appropriate ingress protection (IP54-rated enclosure). Data integrity aligns with GLP principles through timestamped logging, operator ID tagging, and non-volatile memory storage (≥10,000 records).

Software & Data Management

Data acquisition and configuration are managed via an embedded 3.5-inch TFT-LCD touchscreen interface with intuitive icon-based navigation. All measurement sessions are automatically stamped with date, time, GPS coordinates (optional external module), ambient T/P, and operator ID. Export occurs via micro-USB or Bluetooth to PC-based software supporting CSV, Excel, and PDF report generation. Audit trail functionality includes change logs for calibration dates, alarm thresholds, and unit preferences—meeting foundational traceability requirements analogous to FDA 21 CFR Part 11 Annex 11 expectations for non-GxP field instruments. Firmware updates are performed via secure USB drive with SHA-256 signature verification.

Applications

• Occupational health monitoring in breweries, greenhouses, fermentation facilities, and HVAC maintenance zones where CO₂ accumulation poses asphyxiation risk
• Rapid-response leak detection in refrigeration systems, LNG terminals, and CO₂ fire suppression installations
• Stack emission screening for combustion sources—including boilers, kilns, and incinerators—prior to formal CEMS validation
• Indoor air quality (IAQ) assessment in schools, offices, and healthcare facilities per ASHRAE Standard 62.1 ventilation guidelines
• Process safety audits for petrochemical refineries and chemical storage depots requiring real-time hydrocarbon + CO₂ co-monitoring
• Environmental site assessments involving landfill gas migration or biogas upgrading verification

FAQ

What calibration standards are required for routine verification?
Certified gas mixtures traceable to NIM (National Institute of Metrology, China) or NIST SRMs—typically CO₂ in N₂ at 100 ppm, 1%, and 5% vol—are recommended for zero/span checks every 30 days or before critical measurements.
Can the GHK-4000 be used in high-humidity environments?
Yes—the optical path incorporates hydrophobic coating and dual-wavelength compensation to mitigate water vapor interference; however, condensation-prone sampling (e.g., saturated stack gas) requires optional heated sampling line and Nafion dryer integration.
Is factory calibration certificate included with shipment?
Each unit ships with a manufacturer’s calibration report listing initial sensitivity, zero drift, and linearity verification against reference standards per JJG 635–2011 Annex B.
How is sensor longevity ensured under continuous field operation?
The modular NDIR cell features sealed optical cavity design with inert gas fill and anti-reflective coatings, delivering ≥24 months typical service life under normal ambient conditions (20–30°C, <80% RH).
Does the device support remote data transmission via cellular or LoRaWAN?
Not natively—but RS-232/485 serial output is available for integration into third-party SCADA or IoT gateways supporting Modbus RTU or ASCII protocols.