Wide-range thermal convection manometer

Abstract

A pressure gauge covering both the Pirani and liquid manometer ranges, easily adaptable for continuous recording, has been devised and successfully operated. In the pressure range of the Pirani gauge, the working principie is that of the thermal conductivity at low pressures; at higher pressures, on the contrary, a convection stream takes place, which depends on pressure and determines temperature variations in the filament. Experimental results give máximum sensitivity in the range 0.5-5 torr and a reasonable sensitivity for pressures up to one atmosphere.