engleski

Improvement of Air Gauges Metrological Properties through Constructional Changes

In the paper, some ideas of improvement of air gauge metrological properties is presented. The researches were directed to the avoiding of the axial symmetry of the outflow and stabilization of the expanding air stream in the flapper-nozzle area. The constructions of air gauges with asymmetrical outflow and with capillary nozzle appeared advantageous in comparison to the typical solution. Under discussion were such constructions as gauge with polygonal measuring nozzle orifice, with skewed measuring nozzles, and capillary inlet nozzle. Polygonal orifices eliminated the axial symmetry of the outflow and had no sharp changes in the sensitivity graph. This made their measuring ranges extended without any loss of sensitivity. Similar results were achieved for the air gauges with capillary inlet nozzles. The skewed-nozzle gauge had an additional advantage: when only one channel was being fed, the other worked as an injector. This enabled to reach better metrological properties in “ passive” channel than in “ active” . Moreover, the signals from each measuring chambers could be treated separately or could be combined, giving additional improvement of the metrological properties.

Air Gauges; Metrological Properties; Nozzle

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