The main objectives are:
- To develop humidity calibration methods and procedures for industrial use for air temperatures above 100 °C and absolute pressures from 0.5 bar to 6 bar. The uncertainty levels appropriate for relevant applications (typically less than 2 % relative humidity) will be achieved with the minimum additional work load and equipment costs.
- To develop humidity calibration methods and procedures for industrial use applicable to transient conditions, including development of a prototype field humidity calibrator. The target is for the uncertainty of the calibration to be the same as when performed under steady state conditions (i.e. better than 2 % relative humidity) but for the time needed for the industrial calibration to be reduced by at least 50 % from up to one day.
- To develop humidity measurement techniques and procedures for the accurate monitoring of temporal and spatial humidity variations in selected applications, including development of a new type of hygrometer based on direct Tuneable Diode Laser Absorption Spectroscopy (dTDLAS) for process environments with temperatures up to 180 °C and a new measurement method for detecting the influence of microbiological processes on the transient humidity conditions within small samples. The target relative uncertainty for the water vapour amount fraction at high temperatures is 5 %, and the uncertainty for the relative humidity measurements will be less than 2 %rh.
- To develop water activity measurement (equilibrium relative humidity) techniques for in-line measurement applications - with a measurement uncertainty smaller than 0.02 - and to develop methods for establishing the traceability link between water activity and water mass fraction measurements including the development of tools for analysing error sources in water activity measurements which are an integral part of sorption isotherm measurements.