# Explain how a spirometer is used to measure lung function and describe what the measurements can tell a doctor about a patient's respiratory health.

> AQA A-Level Physics (7408) — 3.10.3 Biological Measurement · Explain · 5 marks

## Mark scheme (5 marks)

1. A spirometer measures the volume of air breathed in and/or out
2. The patient breathes into the spirometer (mouthpiece/tube) and the changes in volume are recorded over time
3. Tidal volume can be measured — the volume of air in a normal breath
4. Breathing rate can be determined from the spirometer trace
5. Abnormal tidal volume or breathing rate can indicate a respiratory condition / reduced lung function

## Key terms

- [spirometer](https://www.gradenine.co.uk/glossary/spirometer)
- [lung function](https://www.gradenine.co.uk/glossary/lung-function)

## Related

- [Revision notes for AQA A-Level Physics (7408)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-a-spirometer-is-used-59883c8b) · Published by Druglandscape Ltd.