Metrology for moisture in materials

Short Name: METefnet, Project Number: SIB64
Water-drops on glass

Moisture in materials: Measuring moisture levels 


Moisture content affects performance, lifespan, processing speed, weight and the price of almost all manufactured products, including paper, food, fuels, pharmaceuticals, glues and coatings. The quality of many industrial products relies on controlling or removing moisture at the end of the production process.

 

During the production process moisture analysers are used to determine how much water is present in a material or product. These analysers are calibrated through comparison with the ‘loss on drying’ technique, which measures how much of the sample’s water volume is evaporated at a controlled temperature. This technique lacks traceability due to the uncertainty around how well moisture is extracted by the evaporation process and how much is from other extracted volatile materials. Increased accuracy and improved links to the SI units will provide industry with the robust measurements required for the quality control of moisture content.

 

This project developed new techniques and reference materials to improve traceability to SI units and the transferral of this to industrial moisture measurements nearer to the production process.

 

The Project:

  • Developed four highly accurate reference methods, one using chemical analysis (titration) and three based on measuring water vapour removal from a sample by drying and validating them through comparison exercises
  • Developed well-defined reference materials, with confirmed homogeneity, stability and lifespan, in order to transfer traceability from NMIs to calibration laboratories
  • Developed a model for predicting how water is absorbed and transported through materials, which could be used to improve product performance, particularly for glues and coatings
  • Developed a novel calibration system, using DRIFT spectrometry, in order to transfer traceability to surface moisture measurement probes. This system measures moisture content based on the changing reflectance of infra-red light.

 

This collaborative project brought together a diverse range of moisture and temperature experts to tackle a lack of traceability and fragmented knowledge in this area across the EU, raising understanding and capabilities across the board. The improved processes developed by the project are now available as two best practice guides on making reliable calibrations, one on titration uncertainty and one on sample handling and transportation uncertainty.

 

Research into moisture in different materials is also having a direct benefit in various industrial sectors. Biofuels companies can now better determine the water content of wood pellets enabling greater combustion efficiency, coupled with reduced CO2 emissions. Agricultural production requires knowledge of soil moisture based on reliable measurements to optimise irrigation for increased crop yields. A follow-on project will link the project’s primary measurement techniques to soil measurement instruments.

Project website
Publications
New Approach for Measuring Moisture in Solids Using Radio Frequency and Microwave
2016

11th International Conference on Electromagnetic Wave Interaction with Water and Moist Substances

Moisture measurement setup for wood based materials and biomasses
2016

International Congress of Metrology 08008 (2015)

Comparison of an NMR-based Bioenergy Moisture Measurement Instrument against the Loss-on-Drying Method
2016

Proceedngs of the 11th International Conference on Electromagnetic Wave Interaction with Water and Moist Substances, Florence, ITALY, 2016

THE COMPARISON OF A MICROWAVE BASED BIOENERGY MOISTURE MEASUREMENT INSTRUMENT AGAINST THE LOSS-ON-DRYING METHOD
2016

Proceedings of XXI IMEKO World Congress, Prague, CZECH REPUBLIC, 2015

Metrological traceability for moisture content analysis in wood pellets
2015

Proceedings of CIM 2015 - 17th International Congress of Metrology

Moisture determination for food quality assessment
2015

Proceedings of CIM 2015 - 17th International Congress of Metrology

Industrial implementation of the new NIR laser-based sensor for measuring surface moisture in poiymers
2015

Proceedings of the 17th International Congress of Metrology 2015

Dynamic properties during wood humidification
2015

17 th International Congress of Metrology, 14009 (2015 )

METefnet: developments in metrology for moisture in materials
2015

17th International Congress of Metrology