A peak flow meter is used to measure your peak expiratory flow rate (PEFR). PEFR describes how quickly your lungs expel air during a forceful exhalation after you fully inhale. Regularly conducting a ...

A peak expiratory flow rate (PEFR) measures how effectively you exhale. Also called a peak flow meter, this handheld device helps you document the amount of air and the speed at which you can ...