Zhongkehuifen ZX-3000 Online Gas Chromatograph

Overview

The Zhongkehuifen ZX-3000 Online Gas Chromatograph is a dedicated, fully automated gas analysis system engineered for continuous, unattended monitoring of high-purity industrial gases—including nitrogen, hydrogen, oxygen, argon, helium, and synthetic air—within semiconductor fabrication, electronics manufacturing, specialty gas production, and ultra-high-purity (UHP) gas distribution environments. Unlike laboratory-based GC systems requiring manual intervention, the ZX-3000 integrates process-integrated sampling, pneumatic valve sequencing, and embedded thermal conductivity detection (TCD) to deliver real-time compositional data with minimal operator dependency. Its core measurement principle relies on gas-phase separation via capillary or packed columns under controlled carrier gas flow, followed by quantitative detection using a robust, drift-compensated TCD detector optimized for permanent gas and light hydrocarbon analysis. Designed for 24/7 operation in controlled ambient environments (e.g., cleanrooms or gas cabinet enclosures), the system emphasizes long-term baseline stability, low maintenance intervals, and resistance to pressure and flow fluctuations inherent in plant-side sampling lines.

Key Features

• Fully automated operation with programmable sequence control—eliminates manual injection, column conditioning, or calibration adjustments during routine operation.
• Electromechanically actuated multi-port sampling valves driven by stepper motors, ensuring precise, repeatable sample introduction and extended service life (>1 million cycles).
• Dual-timing injection logic enables flexible cycle definition: one timer governs sample loop fill duration; the second controls injection event timing—both adjustable in real time via front-panel interface or remote command.
• Integrated TCD detector with ≥4000 mV·mL/mg sensitivity (measured against benzene standard) and <1% relative standard deviation (RSD) for repeated injections—meeting performance benchmarks for trace impurity quantification in UHP gases.
• Onboard data handling: chromatograms auto-display on integrated LCD screen, are timestamped and stored internally (≥10,000 runs), and support USB export for external archiving or LIMS integration.
• Modular hardware architecture facilitates field-replaceable components—including detector cells, valves, and column ovens—reducing mean time to repair (MTTR) and supporting lifecycle extension beyond typical OEM service windows.

Sample Compatibility & Compliance

The ZX-3000 is validated for direct analysis of non-corrosive, non-condensable gases at ambient or slightly elevated pressures (up to 1.5 MPa inlet). Compatible matrices include bulk inert gases (N₂, Ar, He), reducing gases (H₂), oxidizing gases (O₂), and binary/multi-component blends used in CVD, etching, and annealing processes. It meets mechanical and electrical safety requirements per GB/T 18268.1–2010 (equivalent to IEC 61326-1) for industrial measurement equipment. While not pre-certified for hazardous area installation (e.g., ATEX or IECEx), it may be deployed in Zone 2 or Class I, Division 2 environments when installed upstream of sampling extractors with appropriate purge or barrier protection. Data integrity complies with basic ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate); optional audit trail logging and electronic signature modules can be added to align with FDA 21 CFR Part 11 expectations for regulated users.

Software & Data Management

The instrument operates via an embedded Linux-based controller with a real-time OS, providing deterministic response for valve timing and detector signal acquisition. Local configuration and diagnostics are accessible through a 7-inch resistive touchscreen with intuitive icon-driven navigation—no PC required for daily operation. Raw analog TCD output (±10 V) and digital metadata (retention times, peak areas, status flags) are logged in CSV-compliant format. Optional Ethernet or RS-485 Modbus RTU connectivity enables integration into DCS/SCADA platforms for alarm forwarding (e.g., O₂ > 1 ppm threshold), trend visualization, and automated report generation. All stored chromatograms retain full spectral fidelity and are exportable without proprietary codec dependencies—ensuring long-term readability independent of vendor software continuity.

Applications

• Real-time monitoring of residual moisture, oxygen, nitrogen, CO, CO₂, and hydrocarbons in high-purity hydrogen used in fuel cell manufacturing.
• Verification of argon/nitrogen purity in sputtering and PVD chamber purge streams prior to wafer loading.
• Leak detection and composition verification in on-site gas generator outputs (e.g., PSA or membrane-based N₂ generators).
• Batch release testing of cylinder-filling stations producing medical-grade or electronics-grade gases per ISO 8573-1:2010 Class 1–2 purity specifications.
• Process troubleshooting in ammonia synthesis loops via continuous NH₃/N₂/H₂ ratio tracking.

FAQ

Is the ZX-3000 compatible with corrosive or reactive gases such as Cl₂, NH₃, or HCl?
No. The standard configuration uses stainless steel wetted parts and a TCD detector unsuitable for strongly adsorbing or chemically reactive species. Custom inertized flow paths and alternative detectors (e.g., PDHID) require engineering review and are not part of the base model.
What level of preventive maintenance is required for uninterrupted operation?
Recommended maintenance includes quarterly carrier gas filter replacement, biannual valve seal inspection, and annual TCD filament resistance verification. No column reconditioning or detector cleaning is needed under normal high-purity gas operation.
Can the system be integrated into a central lab information management system (LIMS)?
Yes—via Modbus TCP or ASCII serial protocol. Structured data export (CSV/TSV) supports manual ingestion into LIMS or ELN platforms without middleware licensing.
Does the instrument support ASTM D1945 or ISO 6974-1 compliant reporting?
Raw data conforms to the quantitative framework of these standards; however, full compliance requires user-defined calibration protocols, certified reference materials, and documented uncertainty budgets per ISO/IEC 17025—functions supported but not pre-configured.
What is the maximum allowable sample line length between the process tap and analyzer inlet?
For optimal response time and minimal band broadening, total sample line length should not exceed 25 meters using 1/8″ OD electropolished stainless steel tubing, heated to 60°C if ambient temperatures fall below 15°C.