Uncertainty of the Air Gauge Test Rig

In the paper, the Advanced Back Pressure Experimental Rig is described and its measurement uncertainty is estimated. The test rig consists of mechanical, pneumatic and electronic systems, which are the main sources of uncertainty. Moreover, operator, environment, A/D conversion and data processing take part in the uncertainty propagation. To perform the uncertainty analysis, mutual impact of the system parts was considered, and the main stages of the data collection and processing were distinguished: setting of the assumed point, reading of its value, reading of the corresponding back-pressure, and the calculation of the examined air gauge characteristics. The analysis confirmed the uncertainty propagation with the largest uncertainty added by the approximation algorithms in the final stage of the process. The equipment variation was evaluated, too, and its value was found satisfactory, especially as it included the repeatability of the tested air gauge itself.