MNK MDL900 High-Purity Multi-Range Gas Dilution System
| Brand | MNK |
|---|---|
| Origin | Beijing, China |
| Model | MDL900 |
| Dilution Range | 100–10,000× (extendable to 10⁵×) |
| Output Flow Rate | 0.5–5 L/min |
| Flow Accuracy | ≤ ±0.5% of reading |
| Flow Repeatability | < ±0.2% RSD |
| Linearity (R²) | > 0.9999 |
| Dilution Accuracy | < ±2% |
| Maximum Back Pressure | 0.5 MPa |
| Compliance | ISO 6145 |
| Calibration Traceability | NIM (National Institute of Metrology, China) |
Overview
The MNK MDL900 High-Purity Multi-Range Gas Dilution System is an engineered solution for precise, traceable, and stable dilution of ultra-high-purity (UHP) gases—designed specifically for calibration gas generation, analytical instrument validation, and reference standard preparation in metrology laboratories, environmental monitoring facilities, and semiconductor process control environments. It operates on the thermal mass flow control principle, implementing dual or multi-stage parallel/series dilution architecture per ISO 6145:2015 (Gas analysis — Preparation of calibration gas mixtures — Gravimetric method and dynamic volumetric methods). Unlike pressure-based or orifice-driven systems, the MDL900 employs calibrated thermal mass flow controllers (MFCs) with real-time digital feedback loops to maintain stoichiometric accuracy across its full operational range—even under variable downstream back pressure up to 0.5 MPa. Its design targets applications demanding sub-ppb-level consistency, such as GC-FID/MS carrier gas spiking, FTIR reference cell filling, and EPA Method 205 compliance testing.
Key Features
- Thermal MFC-based dilution architecture with NIM-traceable calibration certificates for each flow channel
- Dual-mode operation: binary (two-gas) and multi-component (≥3 input gases) dilution configurations supported via modular valve manifold
- Extended dilution ratio capability: 100× to 10,000× standard range; configurable up to 10⁵× via cascaded dilution paths
- VCR-fitting + orbital weld internal tubing assembly—electropolished 316L stainless steel, helium-leak tested to <1×10⁻⁹ mbar·L/s—ensuring compatibility with UHP gases (e.g., 99.9999% Ar, He, N₂, H₂)
- Constant output flow maintenance: maintains setpoint flow (0.5–5 L/min) regardless of dilution factor—minimizing carrier gas consumption without compromising delivery stability
- Integrated back-pressure tolerance: validated operation at sustained outlet pressures up to 0.5 MPa, enabling direct coupling to pressurized analyzers (e.g., cavity ring-down spectrometers, laser absorption systems)
Sample Compatibility & Compliance
The MDL900 is compatible with inert, reactive, and corrosive gases—including but not limited to nitrogen, argon, helium, hydrogen, oxygen, carbon monoxide, sulfur dioxide, and ammonia—provided appropriate wetted material selection (e.g., Hastelloy C-276 optional for aggressive species). All flow paths are passivated per ASTM A967 and certified for oxygen service when required. The system complies with ISO 6145:2015 for dynamic dilution methodology and meets the metrological requirements of China’s JJG 857–2016 verification regulation for gas diluters. As supplied, it includes NIM-issued calibration reports with uncertainty budgets conforming to GUM (JCGM 100:2008), supporting GLP/GMP audit readiness and ISO/IEC 17025 accreditation pathways.
Software & Data Management
The MDL900 operates via a dedicated embedded controller with RS-232, RS-485, and optional Ethernet interfaces. Configuration, real-time monitoring, and event logging are managed through MNK’s DiluSoft™ v3.2 software—supporting SCADA integration, CSV export, and time-stamped audit trails compliant with FDA 21 CFR Part 11 (electronic signatures, user access levels, and change history). All flow setpoints, actual readings, temperature/pressure compensation parameters, and calibration coefficients are stored locally with non-volatile memory retention (>10 years). Firmware updates are performed via secure signed packages; configuration files support version-controlled deployment across multi-unit installations.
Applications
- Preparation of certified reference materials (CRMs) for EPA, EN, and ISO regulatory methods
- Calibration of continuous emission monitoring systems (CEMS) and ambient air quality analyzers (e.g., NOₓ, SO₂, O₃ chemiluminescence detectors)
- Dynamic generation of low-concentration challenge gases for sensor response testing and drift assessment
- Carrier gas spiking in high-resolution gas chromatography and isotope ratio MS
- Validation of photolysis reactors and atmospheric simulation chambers requiring ppm-to-ppt gas dosing precision
FAQ
Does the MDL900 support automated calibration verification routines?
Yes—DiluSoft™ includes built-in verification protocols that execute sequential zero/span checks using integrated reference flow sensors and trigger alerts if deviations exceed user-defined thresholds.
Can the system be integrated into a centralized lab automation network?
Yes—Modbus RTU/TCP and OPC UA profiles are available upon request; hardware I/O terminals support dry-contact triggers for external PLC synchronization.
Is third-party calibration by accredited labs (e.g., UKAS, DAkkS) supported?
Yes—NIM calibration data serves as baseline; full re-calibration services—including uncertainty evaluation per ISO/IEC 17025—are offered through MNK’s global partner network.
What maintenance intervals are recommended for long-term accuracy retention?
Thermal MFCs require annual functional verification; VCR joints and filters should be inspected quarterly in UHP service; full system recalibration is recommended every 24 months or after 2,000 operating hours.
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