A peak flow meter is an inexpensive, pocket-size device that
measures peak expiratory flow (PEF), or how much air a person can breathe out. To
measure PEF, the person takes a deep breath and then blows into a tube on the
peak flow meter as hard and as fast as possible. This can be done at
Peak flow meters come in many shapes and sizes.
ByHealthwise Staff Primary Medical ReviewerJohn Pope, MD - Pediatrics Specialist Medical ReviewerLora J. Stewart, MD - Allergy and Immunology