Extech an300320 anemometers with temperature extech an320 extechs an300 series of 10cm 4in large vane thermo anemometers allows for more precise readings on larger size ducts each meter simultaneously displays airflow or air velocity and temperature applications include hvac manufacturing engineering appliance testing research and design and more the an320 measures air velocity and air flow air temperature and perfoms multipoint and timed average calculations with minmax and