Project presentation

Progress beyond the state of the art and results


Measurement of humidity (water vapour) in gases spans more than nine orders of magnitude, addressing diverse scientific and industrial applications. Humidity needs to be known in various matrices, from process gas mixtures to UHP gases where, in fact, water is the single largest matrix contaminant. While mid-to-high range have been investigated and standards do exist, there is still a lack measurement traceability to underpin trace water measurements.

Water vapour is a critical contaminant in vacuum systems and UHP gases. According to the International Technology Roadmap for Devices and Systems (formerly ITRS), water vapour measurement techniques need to measure amount fractions as low as few parts per billion at the point of use. From 2015 to 2020 these requirements have tightened for some gases (nitrogen, argon) by more than 5-fold. This presents great challenges to both gas producers and analytical instrument makers.

In trace water measurement in gases, several effects have a significant impact on the measurement accuracy and need to be thoroughly investigated to underpin measurement traceability of new/improved products, thus facilitating their acceptance by the industry.