English Product Name

Overview

The CMH-01 Portable Precision Chilled-Mirror Dew Point Meter is a laboratory-grade, direct-reading hygrometer engineered for high-accuracy, traceable dew point measurement across industrial and research environments. It operates on the fundamental physical principle of chilled-mirror condensation hygrometry: a polished mirror surface is cooled under controlled conditions until dew (or frost) forms, at which point the mirror temperature—measured with a calibrated PT100 sensor embedded directly in the mirror substrate—is recorded as the thermodynamic dew point temperature. This first-principles method eliminates reliance on empirical calibration curves or polymer-based sensors, delivering inherently traceable, drift-free measurements compliant with ISO 8503-1, ASTM D2245, and IEC 60068-2-30 for humidity testing. Designed for field-deployable precision, the CMH-01 integrates a four-stage Peltier cooling module capable of achieving >95 °C thermal differential, enabling reliable detection down to −70 °C dew point under standard atmospheric pressure (101.3 kPa), with dynamic range adaptation based on ambient conditions (e.g., −65 °C at 25 °C ambient). Its optical detection system employs dual photodiodes to monitor real-time reflectance changes during condensation onset, ensuring unambiguous phase transition identification without hysteresis or lag.

Key Features

• Direct chilled-mirror measurement principle—traceable to thermodynamic definitions of dew point, eliminating sensor drift and calibration dependency
• Four-stage Peltier cooler with cold-pipe heat dissipation architecture, delivering stable sub-ambient cooling performance and extended low-dew-point capability
• Integrated QCA (Quick Condensation Accelerator) module for rapid stabilization in ultra-dry gas streams (e.g., SF₆, electronic-grade N₂, dry air <1 ppmv H₂O)
• Real-time multi-parameter display: dew point temperature (°C), volumetric moisture concentration (μL/L or ppmv), dynamic condensation curve, sample flow rate (L/h), ambient temperature and RH
• Automatic mirror inspection and adaptive optical gain control—self-adjusts LED intensity based on mirror reflectivity and contamination level
• True-color 320×240 TFT LCD with graphical condensation progress visualization and full-curve tracking during equilibration
• Built-in rechargeable Li-ion battery supporting ≥8 hours of continuous operation; AC/DC universal charging interface with overvoltage/overcurrent protection
• Robust mechanical design (4 kg, IP20-rated enclosure) optimized for transport between labs, field sites, and process lines

Sample Compatibility & Compliance

The CMH-01 supports quantitative dew point analysis of non-corrosive, non-condensable gases including compressed air, instrument air, nitrogen, oxygen, argon, SF₆, natural gas, liquefied petroleum gas (LPG), refrigerants (R-134a, R-410A), and insulating gases used in high-voltage equipment. It accommodates inlet pressures from 1 kPa to 1 MPa and flow rates of 15–60 L/h, with optimal performance at 25–30 L/h. All wetted components are chemically inert stainless steel and sapphire-coated optics, minimizing adsorption artifacts and cross-contamination. The instrument complies with electromagnetic compatibility standards (IEC 61326-1), safety requirements (IEC 61010-1), and supports audit-ready data integrity when paired with optional NIM (National Institute of Metrology, China)-traceable calibration certificates. While not pre-certified for FDA 21 CFR Part 11, its secure local data logging (with timestamped records, user ID tagging, and immutable storage) provides a foundation for GLP/GMP-compliant deployment in pharmaceutical and semiconductor manufacturing QA/QC workflows.

Software & Data Management

Data acquisition and reporting are managed via embedded firmware with no external PC dependency. Measurement records—including dew point, ppmv, flow, ambient conditions, and condensation kinetics—are stored internally with time/date stamps and user-defined sample IDs. Up to 10,000 readings can be retained and exported via USB 2.0 to CSV files for post-processing in Excel or LIMS platforms. Optional PC software enables remote configuration, real-time graphing, report generation (PDF/Excel), and firmware updates. All logged data include metadata on mirror status, cooling current, optical signal strength, and alarm events—enabling full forensic traceability. The system supports dual-language UI (English/Chinese) and configurable units (°C/°F, ppmv/ppb, L/h/m³/h), facilitating multinational lab integration.

Applications

• Petrochemical & refining: moisture monitoring in pipeline natural gas, amine-treated feedstocks, and sulfur recovery unit off-gas
• Power generation: SF₆ purity verification in GIS switchgear, transformer oil gas analysis support, and turbine inlet air drying validation
• Electronics manufacturing: qualification of ultra-high-purity (UHP) process gases (N₂, Ar, O₂) per SEMI F21 and ASTM E2554
• Pharmaceutical packaging: validation of residual moisture in blister foil lidding and lyophilization chamber purge gas
• Aerospace & defense: environmental control system (ECS) bleed air dryness certification and avionics bay humidity mapping
• Nuclear facilities: primary coolant gas dryness assurance and glovebox atmosphere monitoring per ANSI N13.1

FAQ

What is the lowest measurable dew point under typical lab conditions?

At 25 °C ambient and 101.3 kPa, the CMH-01 achieves −65 °C dew point; at 20 °C ambient, it extends to −70 °C dew point.

Does the instrument require periodic recalibration?

No routine recalibration is needed due to its primary-standard chilled-mirror principle; however, annual NIM-traceable verification is recommended for ISO/IEC 17025 compliance.

Can it measure corrosive gases such as HCl or Cl₂?

No—only non-corrosive, non-reactive gases are supported. For aggressive media, consult application engineering for compatible sampling interfaces or dilution systems.

How does the QCA function improve measurement speed for dry gases?

The QCA applies transient thermal modulation to accelerate nucleation onset on the mirror surface, reducing equilibration time from >15 minutes to 3–5 minutes in gases below −40 °C dew point.

Is the battery pack replaceable in the field?

Yes—the Li-ion module is user-serviceable with standard Torx tools and carries CE/UN38.3 certification for air transport.