The DF760 hood is used to measure ventilation and exhaust air in HVAC systems. The instrument consists of a gauge, a nylon hood, a handle and a base. The struts used in the air volume hood are made of fiberglass to provide strong support for the hood. The measuring rectangle of the air volume hood is arranged on the base of the air volume hood, and accurate measurement is realized through 16 measuring points covering the upper section and the lower section of the base of the wind volume hood; and the wind volume hood uses a differential pressure sensor for measurement, and meanwhile, the atmospheric pressure can be corrected.