Red Seal Instrumentation and Control Technician Practice Exam

Which of the following is a common application of a thermocouple?

1. Measuring electrical current

2. Monitoring liquid flow rates

3. Measuring temperature at various points

4. Calibrating pressure transducers

The correct answer is: Measuring temperature at various points

A thermocouple is a device that converts thermal energy into electrical energy, specifically designed for measuring temperature. It consists of two different metal wires joined at one end, which generates a voltage proportional to the temperature difference between the junction and its other ends. This property makes thermocouples particularly useful for measuring temperature at various points, allowing for precise thermal monitoring across a range of applications in different industries. In contrast, the other options involve measurements that do not pertain to thermal properties. Measuring electrical current requires specific instruments like ammeters, while monitoring liquid flow rates generally utilizes flow meters, which could be based on various principles such as differential pressure or magnetic flow measurement. Calibrating pressure transducers involves comparing the readings of a transducer against a known standard, typically using pressure gauges rather than temperature-measuring devices. Hence, the application of thermocouples is uniquely suited for monitoring temperature, validating the correctness of this choice.