Which instrument uses dissimilar metals to measure temperature and generates a voltage proportional to temperature difference?

Prepare for the Engineman EN A School Test 1. Utilize flashcards and multiple choice questions with detailed explanations to boost confidence and readiness for the test.

The main idea here is the Seebeck effect: two dissimilar metals joined together produce a small voltage when their temperatures are different. A thermocouple uses this principle to measure temperature by generating a voltage that is proportional to the temperature difference between the measuring junction and a reference junction. The voltage is tiny, so you compare it to known tables or use cold-junction compensation to convert it into a temperature reading. This makes thermocouples ideal for a wide range of temperatures and fast response.

Other sensors don’t rely on dissimilar metals producing a voltage. An RTD and a thermistor measure temperature by how their resistance changes with temperature, not by generating a voltage. A barometer measures atmospheric pressure, not temperature.