Expansion of European research capabilities in humidity measurement

Humidity is one of the most important properties affecting everyday processes - from indoor ventilation to the storage of food products, textiles, paper and pharmaceuticals. Commercially, humidity measurements are used wherever there is a need to prevent condensation, corrosion, mould, warping or other spoilage of products.
In 2017, although humidity measurements had matured to a level where traceable calibration was beneficial to all industries, many European National Metrology Institutes (NMI) and Designated Institutes (DI) received feedback from clients, indicating a desire for improved uncertainties in humidity measurement. Due to the tightness of manufacturer’s specifications and the difficulty in achieving the uncertainties necessary to verify these specifications, there was an urgent need to improve the uncertainty of relative humidity and dew point measurements in most emerging European NMIs and DIs.

This project addressed research capacity in the field of dew point measurements, the content of water vapour in a gas, by undertaking a systematic review and improvement of dew point generators at each of the emerging NMI or DIs in the project’s consortium.

A new inner chamber for the calibration of relative humidity (RH) instruments was designed and developed to use in combination with the climatic chambers already existing in humidity laboratories.

The new RH chamber covered the relative humidity range 2 %rh - 95 %rh and was characterised in an intercomparison in the temperature range from -60 °C to 100 °C. 26 out of the 28 measurements showed improved measurement uncertainties.

The project also established a methodological approach for building new dew point generators and for allowing development of traceability in dew point measurements

To extend metrological knowledge, two training courses were held for project partners during the project to discuss all aspects of humidity measurements as well as the installation, set-up, and fine tuning of the new RH chamber system.

The metrology institutes of Serbia (DMDM), Bosnia and Herzegovina (IMBiH), Montenegro (MBM), Ireland (NSAI), North Macedonia (BoM), and Croatia (FSB-LPM) prepared individual strategy documents for humidity research and development and associated capabilities, establishing traceable measurements in humidity at the level needed by each participating country.

The upgraded skills and expertise in emerging countries’ NMI/DIs has already had a benefit for their clients in the area of humidity measurements and humidity calibrations and, in the long term, will ensure a more coordinated approach to humidity measurements in Europe.