Which device makes or breaks contacts when a set pressure is reached?

• A. It logs pressure data.
• B. It converts pressure to a digital reading.
• C. It is a manual valve actuator.
• D. It makes or breaks contacts when pressure reaches a set value.

Answer: (D)

The concept here is a device that closes or opens electrical contacts when the pressure reaches a preset value. That is a pressure switch. It’s designed to give a discrete on/off signal at a specific pressure point, which makes it ideal for triggering alarms, interlocks, or automatic shutdowns in a system.

This matches the idea of “making or breaking contacts at a set pressure” because the switch physically changes its electrical state when the pressure threshold is reached.

Logging pressure data, or recording measurements over time, is the job of a data logger, not a contact-switching device. Converting pressure to a digital reading is the role of a pressure transmitter or transducer, which provides a continuous electrical signal proportional to pressure. A manual valve actuator is the mechanism that physically moves a valve, rather than changing electrical contacts based on pressure.