CMC TMA-404 P₂O₅ Electrolytic Moisture Analyzer for Chlorine and Hydrogen Chloride
| Brand | CMC (HimSi) |
|---|---|
| Origin | Germany |
| Model | TMA-404 |
| Type | In-line Dew Point / Moisture Analyzer |
| Principle | Phosphorus Pentoxide (P₂O₅) Electrolytic Method |
| Operating Temperature | 5–50 °C |
| Accuracy | ±1% of full scale |
| Repeatability | ±0.1% of full scale |
| Measurement Range | 0–1 / 10 / 100 / 1000 ppmᵥ (auto/manual range switching) |
| Response Time (T₉₀) | <1 s |
| T₅₀ Response | <8 s |
| Sample Flow Rate | 20 NL/h |
| Recommended Sample Pressure | 0.1–0.5 barg |
| Display | Touchscreen with multilingual UI (including Chinese) |
| Analog Output | 0/4–20 mA (configurable) |
| Alarm Outputs | 2 relay outputs |
| Power Supply | 80–230 VAC, 50–60 Hz |
| Enclosure Options | Rack-mount (482 × 133 × 350 mm), Wall-mount (300 × 260 × 280 mm), Bench-top (257 × 160 × 316 mm) |
| Weight | ~6 kg |
Overview
The CMC TMA-404 is a high-precision, in-line electrolytic moisture analyzer engineered for trace water quantification in aggressive, corrosive, and reactive process gases—particularly chlorine (Cl₂), hydrogen chloride (HCl), sulfur dioxide (SO₂), hydrogen sulfide (H₂S), and other high-purity acid gases. It employs the internationally recognized phosphorus pentoxide (P₂O₅) electrolytic measurement principle: water vapor in the sample gas is irreversibly electrolyzed at a hygroscopic P₂O₅-coated sensor, generating hydrogen and oxygen. The resulting electrolysis current is stoichiometrically proportional to the water concentration (per Faraday’s law), enabling absolute, calibration-free measurement without reliance on empirical correlation or reference standards. This fundamental electrochemical approach ensures long-term stability, eliminates drift-related recalibration cycles, and delivers metrologically traceable results compliant with ISO 8573-8 and ASTM D7443 for compressed gas purity certification.
Key Features
- True absolute measurement principle—no zero/span calibration required under stable operating conditions
- P₂O₅ sensor with dual platinum or rhodium electrodes housed in borosilicate glass, optimized for chemical inertness in Cl₂/HCl environments
- Full microprocessor control with auto-ranging (0–1 / 10 / 100 / 1000 ppmᵥ) and real-time signal compensation for temperature and flow variations
- Sub-second T₉₀ response (<1 s) and rapid T₅₀ (<8 s), critical for dynamic process monitoring and closed-loop control integration
- Integrated self-diagnostics at power-on and continuous sensor health monitoring per NAMUR NE 43 guidelines
- Rugged industrial enclosure options—including 19″ rack-mount, wall-mount, and bench-top configurations—with IP54-rated front panel and reinforced cable glands
- Configurable 4–20 mA analog output with HART® compatibility (optional) and two independently programmable relay alarms for high/low limit or fault conditions
Sample Compatibility & Compliance
The TMA-404 is validated for continuous operation with non-oxidizing, non-reducing, and non-complexing gases that do not chemically degrade P₂O₅ or react with phosphoric acid (H₃PO₄) films. It is widely deployed in chlor-alkali plants, semiconductor etch gas delivery systems, and specialty gas production where Cl₂ and HCl purity must meet ISO 8573-1 Class 1 (≤0.1 ppmᵥ H₂O) or SEMI F57 specifications. While compatible with inert gases (He, Ar, N₂, Xe), oxidizers (O₂, O₃), and halogens (F₂), it excludes gases known to hydrolyze or reduce P₂O₅ (e.g., NH₃, amines, silanes). All units comply with CE marking requirements, EMC Directive 2014/30/EU, and Low Voltage Directive 2014/35/EU. Optional firmware supports audit trails and electronic signatures aligned with FDA 21 CFR Part 11 for GMP-regulated environments.
Software & Data Management
The embedded touchscreen interface provides local configuration, real-time trend visualization, data logging (up to 30 days at 1-min intervals), and alarm history review. USB export enables CSV-formatted data transfer for offline analysis in LIMS or SCADA platforms. Optional CMC Link™ PC software supports remote monitoring via Modbus TCP or RS-485, configurable alarm notifications (email/SNMP), and automated report generation per ISO/IEC 17025 documentation requirements. Data integrity safeguards include write-protected memory, timestamped event logs, and password-protected parameter access levels (Operator/Engineer/Administrator).
Applications
- Real-time moisture monitoring in chlorine liquefaction and cylinder-filling lines
- HCl gas purity assurance for PVC production and semiconductor metal etching
- Quality control of SO₂ and H₂S in desulfurization off-gas streams
- Validation of purge gas dryness prior to catalyst activation in petrochemical reactors
- Trace moisture verification in SF₆ reclamation systems for high-voltage switchgear
- Supporting ISO 8573-8 Annex A compliance testing for compressed air and technical gases
FAQ
Does the TMA-404 require periodic calibration?
No—its P₂O₅ electrolytic principle provides absolute measurement based on Faraday’s law; only sensor regeneration (via controlled anodic current) is needed after prolonged exposure to >1000 ppmᵥ moisture.
Can it operate continuously in 100% chlorine gas?
Yes—the sensor assembly uses corrosion-resistant electrode materials and sealed glass construction, validated for uninterrupted service in dry Cl₂ up to 10 bar partial pressure.
What maintenance is required?
Annual visual inspection of inlet filters and sensor window clarity; optional biannual P₂O₅ film regeneration using the built-in regeneration mode.
Is the instrument suitable for hazardous area installation?
The base unit is rated for Zone 2/Class I Div 2; explosion-proof variants (ATEX II 2G Ex db IIB T4 Gb) are available upon request.
How is sensor longevity affected by high-moisture excursions?
Transient exposure to >1000 ppmᵥ causes reversible saturation; sustained exposure may necessitate field regeneration or factory refurbishment—but does not compromise baseline accuracy post-recovery.
