Measurement of gas humidity

Gas humidity describes the water content in a gas. In many processes, it has a direct impact on product quality, process stability and operational reliability and can be cited and conveyed in different units.

Measuring humidity in everyday life

The measurement of gas humidity forms the basis for process monitoring and quality assurance in numerous technical applications. It is used, among other things, in building and air-conditioning technology to regulate the indoor climate, in meteorology to determine the water vapour content of the atmosphere and in industrial processes to maintain defined humidity conditions. Depending on the application, gas humidity influences product quality, process stability, system availability and energy consumption, among other things.

At METAS, we ensure the traceability of thermodynamic humidity variables (absolute and relative humidity) to the International System of Units (SI) and make them available to business, research and administration as well as to verification offices and verification laboratories.

Typical applications of humidity measurement

• Industry and process technology: for process monitoring and quality assurance
• Pharmaceutical industry: for controlling defined humidity conditions
• Food industry: to ensure production and storage conditions
• Semiconductor production: for precise humidity control in sensitive processes
• Compressed air and process gas systems: for monitoring and avoiding humidity problems
• Air conditioning and building technology: for controlling the indoor climate and energy efficiency
• Meteorology and environmental measurement technology: for weather observation and climate analysis
• Energy and plant technology: for checking humidity parameters in technical systems
• Research and laboratory: for reference measurements and test methods

Our services in the field of humidity

In the field of humidity, we offer the following calibration services:

• Calibration of dew point hygrometers and dew point sensors (-60°C to +90°C)
• Calibration of H₂O gas spectrometers (10 ppm to 10000 ppm)
• Calibration of instruments and sensors for measuring relative humidity (-10°C to 70°C / 10% RH to 95% RH)
• Calibration of other hygrometers

Is the service you are looking for not listed on the website? Please do not hesitate to contact us so that we can work together to find a customised solution to your problem.

Measuring methods and technologies

The measurement of thermodynamic humidity values is based on the determination of the water vapour content in gases under defined conditions. Various measurands such as dew point, relative humidity, absolute humidity or mixing ratios are used to clearly describe the humidity state of a gas.

METAS generates the reference gas humidity based on fundamental thermodynamic relationships. This makes it possible to generate defined reference conditions with high accuracy. The moisture content of a gas is generated by carefully adjusting temperature and pressure, and ensuring a vapour–liquid equilibrium in so-called humidity generators.

Quality and expertise

You can find information on the quality of our services on the “Integrated Management System” page.

Enquiry and contact

Laboratory DC and Low Frequency
Federal Institute of Metrology METAS
Lindenweg 50
3003 Bern-Wabern

T [phone]
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