Glossary · Sensors and measurement
Level sensor
Also known as: Level transmitter, Level switch
German: Füllstandsensor
In process instrumentation, a level sensor is a sensor that detects or measures the level of liquids or bulk solids in a vessel, either as a point level (switching signal) or continuously over a range.
- Sensors
- Process industry
In one sentence
A level sensor detects or measures the fill level of liquids or bulk solids, either at a set point or continuously over a range.
Example
A guided-wave radar level sensor measures the level in a buffer tank, while a vibrating fork switch at the top protects it against overfilling.
How it applies
- Engineering: Choose between point level and continuous measurement first, then the principle: radar, ultrasonic, hydrostatic, capacitive, vibrating, float or conductive. Medium properties such as foam, build-up, dust and dielectric constant rule out some principles.
- Commissioning: Enter tank geometry and reference points, and verify the reading against a known level.
- Operation: Overfill and dry-run protection may form part of a safety or environmental protection function; then the sensor and its logic are part of a designed protective system, not just a process signal.
- Documentation: Document the reference point and the meaning of 0 % and 100 %. Operators, engineers and service technicians often assume different reference points.
Level sensor vs. level switch
A level switch delivers only a switching signal at one height; a level transmitter delivers a continuous value. Both are level sensors in the broad sense.