CMC iTMA-202-W P₂O₅ Electrolytic Trace Moisture Analyzer for Chlorine Gas
| Brand | CMC |
|---|---|
| Origin | Germany |
| Model | iTMA-202-W |
| Product Type | Online Dew Point Analyzer |
| Measurement Principle | Phosphorus Pentoxide (P₂O₅) Electrolytic Method |
| Operating Temperature | 5°C to +50°C |
| Accuracy | ±1% of full scale |
| Repeatability | ±0.1% of full scale |
Overview
The CMC iTMA-202-W is a high-precision, in-line trace moisture analyzer engineered specifically for demanding industrial gas applications—particularly corrosive and reactive process streams such as chlorine (Cl₂), hydrogen chloride (HCl), sulfur dioxide (SO₂), and hydrogen sulfide (H₂S). It employs the fundamental electrochemical principle of phosphorus pentoxide (P₂O₅) electrolysis: water vapor in the sample gas is quantitatively decomposed into hydrogen and oxygen at a P₂O₅-coated sensor cell, generating an electrolytic current directly proportional to the moisture concentration. This absolute measurement method eliminates reliance on calibration gases or periodic recalibration under stable operating conditions, ensuring long-term metrological integrity. Unlike capacitive or chilled-mirror technologies, the P₂O₅ electrolytic technique delivers true zero-baseline stability and immunity to condensable hydrocarbons or particulate interference—critical for ultra-trace moisture detection down to sub-ppm levels in high-purity chemical manufacturing, semiconductor feedstock handling, and chlorine-based disinfection systems.
Key Features
- True absolute measurement: No drift compensation or span gas required; sensor regeneration restores baseline performance without hardware replacement
- Ultra-fast response: T₅₀ ≤ 8 seconds; full stabilization < 1 second for dynamic process monitoring
- Auto-ranging capability across four selectable spans: 0–10 ppm, 0–100 ppm, 0–1000 ppm, and 0–2500 ppm v/v
- Integrated touch-screen HMI with multilingual support (English default; Chinese optional)
- NAMUR-compliant output interface: Configurable 4–20 mA analog output with HART protocol support
- Dual programmable relay outputs for alarm and fault signaling per IEC 61508 SIL 1 requirements
- Robust sensor architecture: Glass-bodied electrolytic cell with platinum or rhodium electrodes and stabilized P₂O₅/H₃PO₄ electrolyte film
- Onboard self-diagnostics: Power-up system check, sensor health verification, and real-time error logging
Sample Compatibility & Compliance
The iTMA-202-W is validated for continuous analysis of inert gases (He, Ar, Kr, Xe, N₂, O₂, D₂), oxidizing gases (O₃, F₂), acid gases (Cl₂, HCl, SO₂, HBr, H₂S), and halogenated compounds (SF₆, Freons, C₂H₂). It excludes only those gases known to chemically attack phosphoric acid films (e.g., strong alkalis or reducing agents with high reactivity toward P₂O₅). Sample conditioning requirements are minimal: flow rate 20 NL/h (±10%), pressure 0.1–0.5 barg, temperature 5–50°C. The analyzer complies with EN 61326-1 (EMC), EN 61000-6-2/6-3, and meets functional safety prerequisites for integration into GMP/GLP environments. Data integrity protocols align with FDA 21 CFR Part 11 expectations when paired with compliant SCADA or DCS historians.
Software & Data Management
The embedded firmware supports time-stamped data logging at user-defined intervals (1 s to 1 h), with internal memory retaining ≥30 days of high-resolution records. USB export enables CSV-formatted traceability for QA/QC review. Optional Modbus TCP or RS-485 RTU communication allows seamless integration into distributed control systems. Audit trail functionality logs all configuration changes, calibration events (if manually initiated), and alarm activations—including operator ID and timestamp—supporting ISO/IEC 17025 and ASTM E2500 traceability frameworks. Firmware updates are performed via secure signed package upload through the web interface.
Applications
- Chlor-alkali production: Real-time Cl₂ drying verification prior to liquefaction or cylinder filling
- Electronics-grade gas supply: Monitoring moisture ingress in bulk Cl₂, HCl, or SF₆ delivery lines to fab tool interfaces
- Pharmaceutical synthesis: Ensuring dryness compliance for moisture-sensitive reagent gases in API manufacturing
- Wastewater treatment: Continuous Cl₂ feed line monitoring to prevent hydrate formation and corrosion in dosing systems
- Chemical storage & transport: In-situ verification of cylinder residual moisture after evacuation and purging
- Regulatory compliance: Supporting ISO 8573-1 Class 1–2 compressed gas purity certification workflows
FAQ
Does the iTMA-202-W require periodic calibration with certified moisture standards?
No—it operates on an absolute electrolytic principle; calibration is not required unless sensor contamination or physical damage occurs. Regeneration restores baseline function.
Can the analyzer measure moisture in wet chlorine containing HCl vapor?
Yes—its P₂O₅ sensor is chemically resistant to HCl co-presence and maintains accuracy up to 5000 ppm HCl at typical process concentrations.
What is the maximum allowable cable length between sensor and transmitter?
Standard shielded cable is supplied at 3 m; extended configurations up to 300 m are supported using low-capacitance, twisted-pair instrumentation cable meeting IEC 60092-350 specifications.
Is the instrument suitable for hazardous area installation?
The base unit is rated for non-hazardous locations (IP65); for Zone 1/2 deployment, it must be installed in an approved purge cabinet or used with an intrinsically safe barrier system (certification documentation available upon request).
How does the auto-ranging function handle transitions between low- and high-concentration gas streams?
The microprocessor continuously evaluates signal-to-noise ratio and automatically switches ranges within 2 seconds while preserving measurement continuity and avoiding zero-shift artifacts.
