Logo of the Physikalisch-Technische Bundesanstalt

Completion of the EMPIR project „Metrology for Humidity at High Temperatures and Transient Conditions“ (EMPIR 14IND11 HIT)


The project aimed to develop humidity calibration methods and measurement techniques for air temperatures above 100 °C in industrial applications. For this purpose, TU Darmstadt has developed a laser based, absolute (dTDLAS) hygrometer, the measurement principle of which was established in accordance with those developed by WG 3.42. The dTDLAS hygrometer was validated for temperatures up to 100 °C by means of a humidity standard in a measurement facility for humidity sensors, which was designed for this purpose at PTB (WG 3.41/3.42). Furthermore, PTB assisted in planning, completion and evaluation of measurements below 100 °C air temperature. Based on the validation by PTB, the dTDLAS hygrometer of TU Darmstadt has been successfully installed and applied at a roast house in Italy by INRIM and TU-Darmstadt.