Measuring head for gas flowmeters - has elastic diaphragm with cut out flap, leaving aperture whose size varies with gas flow

摘要

The gas flow measuring head consists of a housing with a gas inlet and outlet lying in a straight line. A diaphragm (25) is placed across the housing (11) inner space between the inlet and outlet (19, 20). The diaphragm (25) is made of an elastic material and has a hole produced by a partly cut-out section which forms a flap (31) connected to the diaphragm and fitting the hole in size and shape. Its sides converge at a point farthest from the hinged part. The size of the opening varies with the gas flow. Pressure gauges (35, 37) are provided on both sides of the diaphragm, which bends so that the through-flow cross section increases as the gas flow increases.