Glossary · Sensors and measurement
Sensor
Also known as: Detector
German: Sensor
In measurement and automation, a sensor is the element of a measuring system that is directly affected by a phenomenon, body or substance carrying the quantity to be measured, and converts it into a signal that can be processed.
- Sensors
- Standards
In one sentence
A sensor is the element that responds directly to a physical quantity and converts it into a signal a controller or instrument can process.
Example
On a filling machine, sensors report bottle presence, fill level, cap position and conveyor speed to the PLC.
How it applies
- Engineering: Sensors are selected by measured quantity, range, accuracy, response time, environment and interface. The signal may be binary, analog or digital and may already contain diagnostics.
- Integration: In the automation pyramid, sensors sit at the Sensor/actuator level, connected to controllers through I/O modules, fieldbuses or IO-Link.
- Safety: Sensors used in safety functions must meet the requirements of that function; the same sensor type can be acceptable in one architecture and not in another.
- Documentation: A consistent sensor list with tag, function, type, range and location is the backbone of electrical, maintenance and spare-parts documentation. Use the same names in the HMI, diagrams and manuals.
Sensor vs. transducer vs. transmitter
A sensor responds to the quantity. A Transducer converts one quantity into another in a defined relationship. A Transmitter converts the sensor signal into a standardized signal for transmission. In everyday usage, the terms overlap.