Spirometry is the volume of air exhaled to the best of one’s ability after maximum inspiration, and includes three components: tidal volume, compensatory inspiratory volume and compensatory expiratory volume. The greater the lung volume, the greater the ability to inhale oxygen and expel exhaust gases, and the greater the body’s ability to supply oxygen. The spirometer is usually used to measure the size of spirometry. Action demonstration: Step 1, preparation for measurement: First, let the patient rest calmly for 10 minutes, turn on the electronic spirometer and choose a mouthpiece that fits the patient’s mouth shape; Step 2, measurement: First, take a deep breath, make the thorax completely open, fit the mouth closely to the mouthpiece and blow evenly, after blowing this breath, let the patient rest and breathe calmly for 1 minute. Then take a second measurement, the second measurement and the first requirement, blowing at a uniform rate, blowing until it can no longer blow. Finally, repeat the measurement for the third time; step 3, read the value: After the three measurements are completed, take the maximum value and record it on the patient’s physical examination form. At this point, the measurement of spirometry is complete. Special tips: 1, when blowing, airflow can not be interrupted, once interrupted, the instrument will automatically count as the end of a measurement; 2, when blowing, the mouthpiece should be close to the face, do not make the blowing gas through the gap between the mouthpiece and the face overflow, otherwise the measurement results; 3, after the measurement of the mouthpiece should be put into a barrel or box sterilization.