Which sensor uses a flexible copper element that expands and contracts with pressure changes?

Which sensor uses a flexible copper element that expands and contracts with pressure changes?

• A. Bellows sensor
• B. Thermocouple
• C. Bourbon tube
• D. Float type

Answer: (A)

Pressure sensors can use different sensing elements, and the one that relies on a flexible, corrugated metal chamber is the bellows type. A copper bellows expands and contracts as pressure inside or around it changes, and that small, elastic deformation is converted into a readable signal. This makes it the best match for a device described as having a flexible copper element that responds directly to pressure changes. A thermocouple, by contrast, measures temperature with the Seebeck effect between two dissimilar metals, not through a flexible copper element reacting to pressure. A Bourdon tube is another type of pressure sensor that uses a curved metal tube that tends to straighten under pressure; it’s a flexible element, but its deformation is in a tube shape rather than a corrugated bellows. A float-type sensor measures liquid level, not pressure.

Pressure sensors can use different sensing elements, and the one that relies on a flexible, corrugated metal chamber is the bellows type. A copper bellows expands and contracts as pressure inside or around it changes, and that small, elastic deformation is converted into a readable signal. This makes it the best match for a device described as having a flexible copper element that responds directly to pressure changes.

A thermocouple, by contrast, measures temperature with the Seebeck effect between two dissimilar metals, not through a flexible copper element reacting to pressure. A Bourdon tube is another type of pressure sensor that uses a curved metal tube that tends to straighten under pressure; it’s a flexible element, but its deformation is in a tube shape rather than a corrugated bellows. A float-type sensor measures liquid level, not pressure.