Sensor: The Bridge Between the Physical and Digital Worlds
A sensor is a device that detects and responds to some type of input from the physical environment and converts it into a measurable signal, typically an electrical signal (analog voltage or digital code). In essence, sensors act as the "senses" of electronic systems, bridging the gap between the physical world and the digital world for measurement, monitoring, and automated control.
How a Sensor Works
The primary function of a sensor involves a process called transduction, which is the conversion of one form of energy into another. The basic operation involves a few key steps:
Receptor/Sensing Element: This part of the sensor is exposed to the environment and detects the physical input, such as heat, light, pressure, or motion.
Transduction: The physical input is converted into a corresponding electrical signal. For example, a thermocouple converts thermal energy (temperature) into a voltage.
Signal Conditioning: The weak electrical signal is typically amplified, filtered to remove noise, and often converted from an analog signal (continuous) to a digital signal (discrete) for processing by a microcontroller or computer.
Output: The conditioned signal is transmitted to the receiving system for analysis, display, storage, or to trigger an action (e.g., turning on an air conditioner or sounding an alarm).
A good sensor is highly sensitive to the measured property, insensitive to other ambient properties (like temperature drift), and does not significantly influence the property it is measuring.