Spirometry is a test that measures airflow into and out of your lungs. It can help diagnose lung diseases such as COPD, asthma, and restrictive lung disease. Learn how to prepare, what to expect, and how to interpret your results. What is an incentive spirometer ? An incentive spirometer (spy-rom-uh-ter) is a simple, plastic medical device that exercises your lungs. Your healthcare provider may recommend that you use an incentive spirometer after an illness, surgery or an injury to your chest or abdomen. A spirometer is an apparatus for measuring the volume of air inspired and expired by the lungs . A spirometer measures ventilation, the movement of air into and out of the lungs. Online shopping for Spirometers - Diagnostics & Screening from a great selection at Industrial & Scientific Store.