peak flow meter
noun
: a device that measures the maximum rate of air flow out of the lungs during forced expiration and that is used especially for monitoring lung capacity of asthmatics
Example Sentences
Recent Examples on the Web It can be done during spirometry or by breathing into a separate device, called a peak flow meter. 
Kimberly Goad, SELF, 11 Nov. 2021 Asthmatics should use peak flow meters, devices that measure the strength of a breath, to monitor how well their airways are staying open, Rizzo said. Sandee Lamotte, CNN, 21 Apr. 2020 Low readings on a peak flow meter, a different portable device that measures lung capacity, can also be a sign of an asthma attack, the Mayo Clinic says. Korin Miller, SELF, 1 June 2018
Kimberly Goad, SELF, 11 Nov. 2021 Asthmatics should use peak flow meters, devices that measure the strength of a breath, to monitor how well their airways are staying open, Rizzo said. Sandee Lamotte, CNN, 21 Apr. 2020 Low readings on a peak flow meter, a different portable device that measures lung capacity, can also be a sign of an asthma attack, the Mayo Clinic says. Korin Miller, SELF, 1 June 2018 Word History
First Known Use
1962, in the meaning defined above
Medical Definition
peak flow meter
noun
ˌpēk-ˈflō- 
: a device that measures the maximum rate of air flow out of the lungs during forced expiration and that is used especially for monitoring lung capacity of individuals with asthma (as to indicate bronchial narrowing)
called also peak expiratory flow meter