Using the PASCO Differential Pressure Sensor to Measure Lung Function

Turning breathing into real data

One of the most powerful ways to make biology and physics feel real is to let students measure something that belongs to them. Lung function does exactly that — and with a PASCO Differential Pressure Sensor, it becomes a safe, visual and genuinely engaging classroom experiment.

This isn’t medical spirometry. It’s an educational model that helps students understand airflow, pressure differences, and how breathing mechanics relate to volume and health.

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What are we actually measuring?

When a student breathes in or out through a tube connected to the sensor:

• Airflow creates a pressure difference

• The sensor measures this tiny change in pressure

• Software plots a pressure–time graph

• With calibration, this can be related to relative lung volume and flow

The moment students see their own breath appear as a live graph, the lesson changes.

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Typical classroom setup

Equipment

• PASCO Differential Pressure Sensor

• Short length of flexible tubing

• Disposable mouthpiece (essential for hygiene)

• PASCO Capstone or SPARKvue software

Method

1. Student breathes normally for baseline data

2. Deep inhalation and slow exhalation

3. Faster breathing for comparison

4. Repeat after light exercise (stairs or star jumps)

Each run produces a clear, interpretable trace — perfect for discussion and analysis.

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Concepts this experiment brings together

This single setup crosses multiple syllabus areas:

Biology

• Ventilation

• Tidal volume

• Breathing rate

• Effect of exercise on respiration

Physics

• Pressure differences

• Flow rate

• Graph interpretation

• Rate of change

Maths

• Area under curves

• Gradients

• Comparing datasets

• Percentage change

It’s a rare experiment that genuinely earns its place across subjects.

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Why this works so well with students

• It’s personal — they are the data source

• Results are instant and visual

• No flames, chemicals or complex setup

• Easy to repeat and improve technique

• Naturally leads to “what if…?” questions

Students quickly start asking:

• Why are some traces smoother than others?

• Why does exercise change the curve?

• What limits lung capacity?

That curiosity is the real win.

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Safety and good practice

• Always use disposable mouthpieces

• Clean tubing between users

• Emphasise this is not a medical test

• No forced exhalation for students with asthma unless agreed

Handled properly, it’s a very low-risk, high-impact practical.

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Why I use this at Hemel Private Tuition

In my lab and studio-based lessons, this experiment works beautifully on camera. Students can:

• See the live graph

• Pause and analyse together

• Overlay multiple runs

• Link theory directly to evidence

It’s exactly the kind of practical that turns revision into understanding.