Sensors

A sensor is a device that detects changes in its environment and converts those changes into signals that can be interpreted by an observer or instrument. These signals can be in the form of voltage, current, resistance, capacitance, frequency, or digital data, and they represent measurable physical properties such as temperature, pressure, position, force, flow, speed, vibration, optical intensity, or humidity.

Importantly, a sensor is not just the sensing element itself. It also includes the physical housing, external connections, and associated signal-processing electronics necessary for operation. Together, these components enable the sensor to provide accurate, reliable measurements that can be used in real-time monitoring or control systems.

The primary functions of a sensor are:

Monitoring – providing real-time data to a display or logging device.

Feedback Control – supplying condition-based information used to maintain system parameters within specified limits.

Intelligent Decision-Making – enabling autonomous operations by feeding data into systems capable of processing complex inputs.

Sensors are also known as transducers, and they form the foundation of data acquisition (DAQ or DAS) systems. These systems typically consist of:

Sensors – to detect and measure physical phenomena.

Signal Conditioning Circuits – to amplify or filter the sensor’s raw signal.

Analog-to-Digital Converters (ADC) – to digitize the analog signal for processing.

Computing Systems with DAQ Software – to store, analyze, and visualize the collected data.

A sensor can output analog or digital signals. In the analog case, it typically generates a voltage proportional to the physical change, which can then be digitized for further processing or display.

For example, position sensors—used to determine absolute or relative position in linear or angular form—are increasingly found in consumer electronics, medical devices, and industrial equipment.

Sensors are essential components that bridge the physical world and digital systems, enabling real-time measurement, control, and automation across countless modern applications.