AIR FLOW MEASURING DEVICE

摘要

Case 2992 IMPROVED AIR FLOW MEASURING DEVICE AND METHOD There is disclosed an improved method and apparatus for measuring air flow through a stator duct of a dynamoelectric machine. The apparatus includes an inlet venturi connectable to the stator duct, a nozzle for producing a pressure drop related to the air flow rate. The pressure drop is measured by two pressure taps, one located upstream of the nozzle and the other located downstream of the nozzle. The improvement includes an adjustable fan located downstream of the nozzle for inducing an air flow through the apparatus that compensates for air leakage between the inlet venturi and the stator duct. The improvement further includes air leakage measuring sensors which compare air flow through the inlet means with an air flow reference in another part of the dynamoelectric machine. The air leakage measuring sensors register a predetermined pressure differential in air flow through the inlet means and the duct when the fan is adjusted to induce the predetermined compensating air flow through the apparatus.