Red Seal Instrumentation and Control Technician Practice Exam

Which method is commonly used to convert a physical measurement into an electrical signal?

1. Signal filtering

2. Modulation

3. Sensing

4. Feedback

The correct answer is: Sensing

The method commonly used to convert a physical measurement into an electrical signal is sensing. In instrumentation and control systems, sensors play a crucial role as they are designed to detect changes in physical parameters such as temperature, pressure, level, flow, and many more. When a sensor detects a physical measurement, it translates that measurable quantity into an electrical signal that can be processed, transmitted, and used for monitoring or control purposes. For example, a thermocouple converts temperature into a voltage signal that corresponds to the thermal reading. This process is essential for enabling electronics to interpret and act upon physical phenomena. The other methods mentioned serve different purposes. Signal filtering is primarily concerned with removing unwanted noise from a signal rather than modifying a physical measurement into an electrical one. Modulation involves altering a carrier signal to encode information, which is distinct from the act of sensing. Feedback refers to a control mechanism that adjusts a system's operation based on the output, rather than the initial conversion of a physical measurement into an electrical signal. This distinction emphasizes the role of sensing as a foundational process in measurement and control systems.