In the fields of medical care and pharmaceutical manufacturing, medical and high-purity gases play a critical role in treatment processes, production, and the operation of equipment. The purity of these gases directly impacts patient safety, treatment efficacy, and the stability of production lines. One of the most critical parameters to be rigorously controlled is the water content (H₂O), especially for applications that require gases to meet high-quality standards as defined by the European Pharmacopoeia (EP).

Moisture Control Requirements for Medical and High-Purity Gases

According to European Pharmacopoeia Monograph No. 1238 – “Medical Air,” compressed medical air used for breathing and as a driving gas in medical devices must have a moisture content not exceeding 67 ppmV, equivalent to a dew point of -45°C. This specification ensures that the air supplied to patients and devices consistently maintains high quality, absolute safety, and eliminates risks associated with excessive moisture.

Typically, medical air is a mixture of approximately 22% oxygen (O₂) and 78% nitrogen (N₂) and is widely used in hospitals to support respiratory functions and to dilute anesthetic gases such as nitrous oxide (N₂O). Exceeding the moisture limit increases the risk of water condensation in gas distribution systems, respiratory equipment, and medical instruments, thereby compromising patient safety and the performance of medical devices.

Furthermore, in systems for producing medical gases, standard gases used in the pharmaceutical or semiconductor industries must maintain extremely low moisture levels—even at the ppb level—to ensure the optimal purity of the final product and the stability of the production process.

Continuous Moisture Monitoring Solution with the DET H₂O Measurement System

To meet the stringent moisture control requirements in medical and high-purity gases, Reecotech proposes a continuous moisture monitoring solution using the DET H₂O measurement system. This system enables real-time monitoring, early warning, and precise control of moisture levels, ensuring that the gas always meets European Pharmacopoeia standards.

Operating Principle

The DET H₂O system employs a dedicated electrochemical sensor based on the principle of electrolytic measurement. This approach allows for accurate quantification of water vapor in gas at very low concentrations while ensuring high stability under demanding environmental conditions.

Key Technical Specifications

• Measurement Technology: Electrochemical measurement.
• Measurement Range:
  • Standard: 0 – 10 ppmV or 0 – 1000 ppmV.
  • Extended: Capable of measuring down to the ppb level, depending on the configuration and specific application requirements.
• Resolution: 0.5 ppmV.
• Communication Protocols: Integrated standard protocols such as Analog 4-20 mA, Modbus RTU, and Profibus, facilitating seamless integration with central monitoring systems (SCADA, BMS, etc.).

Key Features

• 24/7 continuous moisture monitoring with real-time data acquisition.
• High accuracy, capable of measuring water vapor at extremely low concentrations (from ppmV to ppbV).
• Easy integration with SCADA and BMS systems via standard communication protocols (Analog 4-20 mA, Modbus RTU, Profibus).
• Rapid alarms when moisture levels exceed preset thresholds, protecting both equipment and gas systems.
• Comprehensive historical data logging, supporting traceability for inspection reports.
• Stable operation under variable pressure and temperature conditions.
• Simplified calibration and maintenance, reducing downtime.
• Compliance with the European Pharmacopoeia (EP) moisture control standards.
• Suitable for clean rooms and production lines requiring ultra-high purity gases.
• Prevents corrosion and oxidation, thereby extending the lifespan of the gas system.