ELTRA CW-800 Dual-Channel Infrared Carbon Dioxide and Moisture Analyzer

Overview

The ELTRA CW-800 is a dual-channel, high-precision infrared analyzer engineered for the simultaneous quantitative determination of carbon dioxide (CO₂) and moisture (H₂O) in solid inorganic and mineralogical samples. It operates on the principle of high-sensitivity solid-state infrared absorption spectroscopy, where evolved CO₂ and H₂O gases—released during controlled thermal decomposition in an electrically heated quartz tube furnace—are swept by ultra-pure nitrogen carrier gas through dedicated, gold-plated infrared detection cells. Each cell is optimized for its target analyte: one tuned to the 4.26 µm asymmetric stretch band of CO₂, the other to the 2.7 µm O–H stretch band of water vapor. The furnace temperature is precisely regulated up to 1000 °C in 1 °C increments, enabling selective release of bound water (e.g., structural OH⁻, hydration water) and carbonate-derived CO₂ without interference from organic volatiles—a critical advantage for geological, construction, and recycling materials where matrix complexity is high.

Key Features

• Gold-plated infrared detection cells ensure long-term chemical resistance against acidic or halogen-containing sample matrices (e.g., fluorinated minerals, chloride-rich slags), eliminating need for halogen scavengers or frequent cell replacement.
• Electronic mass-flow-controlled carrier gas system maintains constant flow rate (±0.5% stability) throughout analysis—no manual regulators or mechanical valves requiring periodic maintenance.
• Modular furnace design with replaceable quartz tube and integrated thermocouple enables traceable temperature calibration and reproducible thermal profiles across batches.
• Single- and multi-point calibration routines support traceable quantification per ISO/IEC 17025 requirements; calibration data, instrument logs, and user actions are time-stamped and exportable for audit trails.
• Rugged industrial-grade chassis (65 kg mass, vibration-damped feet) ensures operational stability in both QC laboratories and production-floor environments with ambient temperature fluctuations.
• Integrated reagent trap configuration—using magnesium perchlorate for H₂O and sodium hydroxide for CO₂ scrubbing—ensures baseline stability and prevents cross-contamination between sequential analyses.

Sample Compatibility & Compliance

The CW-800 accepts homogeneous powders, granules, or crushed solids loaded into standardized quartz boats (typical mass: 0.1–1.0 g). It is routinely applied to cement clinker, limestone, gypsum, fly ash, soil aggregates, mining ores, and recycled construction debris. All measurement protocols align with ASTM E1087 (standard test method for carbonates in soils), ISO 11725 (determination of CO₂ in limestone and dolomite), and USP (loss on drying and residual solvents). Software supports 21 CFR Part 11-compliant user authentication, electronic signatures, and immutable audit logs—fully compatible with GLP and GMP quality systems. CE marking and IEC 61010-1 safety certification are factory-verified.

Software & Data Management

ELTRA’s proprietary WinElement software (v5.x) provides full instrument control, real-time spectral monitoring, and automated calculation of CO₂ and H₂O mass percentages based on calibrated IR absorbance integrals. The interface supports English, German, French, Spanish, and Chinese language packs; report templates are customizable per client LIMS requirements (CSV, PDF, XML export). Raw absorbance traces, furnace temperature profiles, and gas flow logs are archived with metadata (operator ID, sample ID, calibration status, timestamp). Data integrity safeguards include write-protected archives, role-based access control, and optional integration with laboratory information management systems via OPC UA or HL7 interfaces.

Applications

• Quality control of hydraulic binders: Quantifying free lime (CaO), combined CO₂, and total moisture in Portland cement and blended cements per EN 196-2.
• Geochemical characterization: Differentiating carbonate-bound CO₂ from organic carbon in sedimentary rocks and mine tailings.
• Environmental remediation: Monitoring moisture content and inorganic carbon in contaminated soils prior to thermal desorption or stabilization.
• Circular economy analytics: Assessing calcination efficiency and residual carbonates in recycled concrete aggregate (RCA) and waste glass fines.
• Raw material certification: Verifying specification compliance for limestone feedstock in lime kiln operations and flue gas desulfurization (FGD) gypsum production.

FAQ

What sample preparation is required prior to analysis?
Samples must be homogenized and dried to constant mass at 105 °C before weighing (0.0001 g precision balance required). No acid digestion or derivatization is needed.
Can the CW-800 distinguish between different forms of water (e.g., adsorbed vs. structural)?
Yes—by programming multi-step temperature ramps (e.g., 150 °C → 600 °C → 1000 °C), users can isolate loss-on-drying (LOD), dehydroxylation, and carbonate decomposition events sequentially.
Is external gas purification necessary for the nitrogen carrier supply?
A dedicated oxygen/moisture trap is recommended upstream of the instrument inlet to maintain baseline stability; ELTRA supplies certified inline purifiers meeting ISO 8573-1 Class 2 specifications.
How often does the IR detector require recalibration?
Under routine use (≤20 samples/day), annual verification against certified reference materials (e.g., CaCO₃ SRM 8546, MgSO₄·7H₂O) is sufficient; software-guided drift correction is available between verifications.
Does the system support unattended overnight operation?
Yes—the autosampler option (up to 40 positions) with integrated balance interface enables fully automated batch processing, including weight acquisition, thermal program execution, and report generation.