peak flow meter

Main Entry: peak flow meter
Pronunciation: "pEk-'flO-
Function: noun
: a device that measures the maximum rate of air flow out of the lungs during forcedexpiration and that is used especially for monitoring lung capacity of individuals with asthma (as to indicate bronchial narrowing) called also peak expiratory flow meter

peak flow meter n.
A portable instrument that detects minute decreases in air flow and that is used by people with asthma to monitor small changes in breathing capacity.