The paper presents the results of studies on local resistance coefficients (ζ). The study used pipe aerators with filling made according to the Polish patent PL235924. The hydraulic investigations were performed in real working conditions of a water treatment plant in a testing rig built in the Scientific and Research Water Station of the Warsaw University of Life Sciences (SGGW). The investigation encompassed two plastic pipe aerators of an internal diameter 101.6 and 147.6 mm with steel Białecki rings of 12 and 25 mm in diameter. Measurements of pressure difference (Δp) in the investigated aerators were performed at volumetric water flows ( Q) selected from the range 2–20 m ³∙h ^–1 with the interval 2 m ³∙s ^–1. The values of ζ were determined according to the PN-EN 1267:2012 standard. The investigation showed that the ζ depends both on an internal diameter of the plastic pipe aerator and the diameter of Białecki steel rings. The values of ζ increase with a decrease of the internal diameter of the pipe aerator and a decrease of the ring diameter.

Ventilation rate is a physical index that is strictly controlled during cigarette manufacturing because an abnormal ventilation rate can affect the release of mainstream smoke, tar, and other components harmful to human health. Therefore, the standard rod is used for measuring the ventilation rate, which necessitates accurate and effective periodic inspections. In this study, we designed and built a set of special tobacco ventilation rate standard rods to assess the standard device during its verification period and used a digital thermal flowmeter as the flow standard.We determined the micro-pressure adjustment interval through fluid simulation, and conducted an experimental verification based on the simulation results. At the adjustment point where the differential pressure value was 0 Pa, the period verification device was tested under the standard values of 27.38%, 58.83%, and 71.95%. The results show that the measurement errors of the device are –0.42%, 0.55%, and –0.13% respectively, which all meet the verification regulation requirements and indicate that the device is applicable in practical situations.