Flow meters
Flow meters monitor the flow velocity or flow rate of gaseous or liquid media. Measurements are reliable and wear-free and also include temperature values. Deviations from individual threshold values that could lead to impaired quality, damage or downtime are detected at early stage, allowing preventive measures to be adopted. Read more here
Cloud compatibleFlow sensors: Precise monitoring of flow media
Flow sensors are crucial for monitoring flow and movement conditions in pipelines and systems, both for gaseous media such as air and nitrogen and for liquid media. They are key components in industrial, process and building services engineering and make a significant contribution to process safety, energy efficiency and plant availability. There are various types of flow sensors, including continuous flow sensors, which enable precise flow measurements, and flow monitors, which can monitor critical conditions and trigger alarms. Correct calibration and selecting the sensor according to the application requirements are essential to ensure high accuracy. At autosen you can get sensors with the following functions:
Flow sensor or flow monitor – what’s the difference?
Flow sensors:
Continuously measure the flow rate and are ideal for precise applications. Depending on the version, in addition to flow they can also provide temperature values and/or diagnostic information.
Flow monitors:
For robust monitoring tasks: the flow monitor detects defined states such as “flow present / not present” or limit violations (exceeding/falling below) and outputs a switching signal – ideal for safety and condition monitoring.
Which media are our flow sensors suitable for?
Flow sensors are used in gaseous media (e.g. air, nitrogen) as well as in liquid media. This makes them versatile for industrial, process and building services engineering – from compressed air supply to cooling and utility systems. Depending on the medium and application, flow sensors are based on different measurement principles. Particularly common are thermal (calorimetric) flow sensors, which evaluate the heat dissipation of a heated sensor element caused by the flowing medium. This method enables high sensitivity, especially at low flow rates, and is ideally suited to clean gases such as air or nitrogen as well as selected liquids. For volumetric flow measurement (e.g. in l/min), flow sensors are alternatively available, while flow sensors are primarily used to monitor flow velocity or flow conditions.
Advantages:
- Non-contact and wear-free
- High sensitivity even at low flow rates
- No mechanical wear
- Well suited to clean gases and liquids
Disadvantages:
- Dependent on the thermal properties of the medium
- Not suitable for heavily contaminated media
- Limited measuring range for very high flow velocities
Application areas for flow sensors
| Industry | Key benefits | Typical added value | Example |
|---|---|---|---|
| Industry & automation |
|
| In an automotive production line, sensors measure compressed air consumption at robots to detect leaks and reduce energy costs. |
| Heating, ventilation and air conditioning (HVAC) |
|
| Monitoring supply and extract air flows in ventilation ducts to plausibility-check fan operation (“Flow OK”). The sensor ensures that when the fan is switched on, there is actually an airflow present; typical measuring range 0…20 m/s. |
| Food and beverage industry |
|
| In a brewery, the CO₂ flow during beer filling is controlled to ensure consistent carbonation. |
| Chemical and pharmaceutical industry |
|
| In a pharmaceutical plant, the flow of water for injection purposes (WFI – Water for Injection) is measured to ensure production quality. |
Not every process has the same requirements – which is why flow sensors are available in different designs and measurement principles. With the right selection according to medium, temperature and flow velocity, you get stable measurement and monitoring results. Find the right flow sensor for your application here or read more about calorimetric flow sensors.
Frequently asked questions (FAQ) about flow sensors
At autosen you’ll find flow sensors for gaseous media (e.g. air/nitrogen) and liquid media – depending on the measurement principle and device version. Many variants also record temperature.
Flow sensors measure the movement of liquids or gases and use various technologies such as ultrasound or magnetic fields.
Flow sensors monitor flow velocity or flow rate and help to detect limit deviations early (e.g. standstill, flow too low). Depending on the application, different measurement principles are used – e.g. calorimetric (thermal), vortex or MID.
Medium properties such as temperature, pressure, density and viscosity, as well as the installation situation, affect the measurement results.
Often yes: inline sensors are usually installed easily between two pipelines. Immersion sensors require a suitable measuring point (e.g. uniform flow) and require more attention to installation conditions. It is important, however, to always follow the manufacturer’s specific instructions.
Many flow/throughput sensors are low-maintenance, especially when they operate without moving parts.
A flow meter measures how much medium flows through a line per unit of time (e.g. l/s or m³/h) – i.e. the quantity/volumetric flow rate. A flow sensor looks at the flow itself, i.e. primarily velocity and flow condition (e.g. laminar or turbulent) and, if applicable, the direction.
In short:
Flow rate = quantity per time,
Flow = behaviour/speed of the medium.














