Glossary · Sensors and measurement
Flow sensor
Also known as: Flow meter sensor
German: Durchflusssensor
In automation and process instrumentation, a flow sensor is a sensor that detects or measures the flow of a liquid or gas through a pipe or channel, as volume flow, mass flow or flow velocity, or as a switching signal when flow is present.
- Sensors
- Process industry
In one sentence
A flow sensor detects or measures the flow of liquids or gases, as volume flow, mass flow or a simple flow or no-flow signal.
Example
A calorimetric flow sensor in the coolant line of a spindle signals the machine controller when coolant flow drops below the minimum.
How it applies
- Engineering: Flow switches (for example calorimetric or paddle types) monitor minimum flow; flowmeters measure the value. The principle depends on medium, conductivity, viscosity, pressure drop and required accuracy.
- Installation: Many principles require straight inlet and outlet runs and a completely filled pipe. The flow direction must match the sensor marking.
- Operation: Flow values should be clearly marked as volume or mass flow and as actual or standard conditions for gases.
- Documentation: State the engineering unit and reference conditions of every flow value in operating instructions and interface specifications. Mixing up actual and standard volume is a frequent source of errors.
Flow sensor vs. flowmeter
Flow sensor is the broad term, including simple flow switches. A flowmeter is a flow sensor that delivers a measured value, often with totalizing functions.