Volume 6, Issue 4 (April 2009)
Uncertainty Analysis in Hygrothermal Measurements and Its Effect on Experimental Conclusions
In hygrothermal measurements a variety of sensors and data acquisition systems are used. Measurement uncertainty is always associated with the experimental work conducted using these devices. Although uncertainty analysis methodology has been well established, performing an uncertainty analysis for a complex hygrothermal measurement system that involves various uncertainty sources and requires multiple levels of uncertainty propagation is not an easy task. Such uncertainty analysis is essential for evaluating the accuracy or “goodness” of the experimental work. More importantly, uncertainty of the measurement is vital in evaluating the validity of the conclusions drawn from the experimental data. Without an appropriate uncertainty analysis, the experimental work cannot be considered complete and the experimental conclusions can be questioned. This paper presents an uncertainty analysis for a vapor pressure measurement system involved in a research project on ventilation drying in wall systems. The influence of the uncertainty on the validity of one experimental conclusion is studied. It demonstrates that considering measurement uncertainty provides a way to understand the experimental conclusion from the probability perspective.