Which device interfaces a temperature sensor to a measurement or control device?

• A. Temperature transmitter
• B. Pressure switch
• C. Proximity sensor
• D. pH probe

Answer: (A)

When connecting a temperature sensor to a measurement or control device, you need signal conditioning and a standard way to transmit the signal. A temperature transmitter does this by taking the sensor output (from a thermocouple or RTD), applying proper compensation and any needed linearization, and converting it to a standard process signal such as a 4-20 mA loop or a 0-10 V signal. This makes the temperature reading accurate, linear, and immune to issues like long cable runs or electrical noise, so the control system can read it reliably.

The other devices have different roles: a pressure switch responds to a set pressure and does not interface temperature signals to a controller; a proximity sensor detects presence or position; a pH probe measures acidity and isn’t used to convey temperature information to a control system.