| 摘要 |
FIELD: instrumentation engineering; polymeric film process lines where it may function as sensor of film thickness automatic control outline. SUBSTANCE: pneumatic device has two opposing aerostatic mounts, two flowmeters for measuring flow rate of air supplied to mounts; the latter are, essentially, fixed air chambers facing each other with their perforated walls; it also has two gage pressure sensors mounted in air chambers and computer unit that functions to calculate film thickness using formula, where δ is film thickness; H is mount-to-mount clearance size; Q, Qis flow rate from chambers 2 and 1, respectively; Pk, Pkis gage pressure in chambers 2 and 1, respectively; K1, K1is factor depending on surface area of respective mount and viscosity of air; K2, K2is factor depending on total surface area of perforated holes of respective mount. Data yielded by device makes it possible to maintain constant thickness of film produced by instantly varying speed of pulling shafts of extrusion machine. EFFECT: improved reliability of measuring device. 2 cl, 1 dwg |
