Air Velocity Sensors

Air Velocity Sensors

Monitoring air flow parameters is an important task in heating, ventilation, and air conditioning (HVAC) systems, as well as in clean rooms, laboratories, and medical facilities. An air velocity sensor allows precise measurement of the intensity of air movement, which is necessary to maintain a comfortable microclimate, ensure safety, and comply with technological processes.

The website features modern models of air flow velocity sensors suitable for various tasks and operating conditions. In this article, we will explain how these devices work, where they are used, and which models deserve attention.

What is an air velocity sensor and why is it needed?

An air velocity sensor is a device that measures the speed of air flow in ventilation ducts, rooms, or technological installations. It allows you to:

• Control the operation of ventilation systems;
• Monitor laminar flows in clean rooms;
• Ensure safety when working with exhaust systems;
• Prevent reverse inflow of contaminated air.

These devices are widely used in HVAC systems, industrial facilities, hospitals, pharmaceutical and scientific laboratories.

How do air flow velocity sensors work?

There are several common technologies for measuring air flow velocity:

1. Thermal Anemometric Sensors

These devices are based on the change in temperature of a heated element under the influence of air flow. When air moves through the sensor, it cools the heated sensitive element, and the flow velocity is calculated based on the amount of cooling.

Model examples:

• SS 20.400 / SS 23.400: Sensor with a low activation threshold, ideal for ventilation systems and clean rooms.
• SS 20.515 LED: Compact thermal anemometric sensor with status indication on an LED panel. Used for monitoring laminar flows in clean rooms.

2. Mechanical (Impeller) Sensors

Mechanical sensors use the rotation of blades or an impeller, the speed of which is proportional to the air flow velocity. These devices are simple to use and reliable in operation.

Model examples:

• ZS25: Series of impeller sensors capable of measuring the flow of air, gases, and various liquids (with viscosity up to 200 cSt). Suitable for various control and automation systems.

3. Differential Pressure Sensors

This type of sensor operates on the principle of pressure difference. When air passes through a special orifice or tube, a pressure difference is created, which is converted into a signal about the flow velocity.

Model examples:

• E2418DP: Converter designed for measuring low air pressure values and non-aggressive gases in heating, ventilation, and air conditioning systems.

4. Flow Velocity Relays

Flow velocity relays are devices that signal when a set air velocity level is reached. They are often used for process automation and equipment protection.

Model examples:

• SS 20.200: Flow velocity relay that can be integrated into ventilation and air conditioning control systems.

5. Combined Sensors

Some models combine several technologies for more precise air parameter control. For example, they can simultaneously measure flow velocity, direction, and temperature.

Model examples:

• SS 20.400: This device with minimal response time is excellent for safe use in clean rooms. These sensors measure not only air velocity values but also direction.

Each type has its advantages and application areas. For example, an air velocity sensor based on a thermal anemometer provides high accuracy even at low velocity values.

How to choose an air flow velocity sensor?

The choice depends on the specific task, operating conditions, and measurement accuracy requirements. Here are the main selection criteria:

• Measurement range: from 0.05 to 220 nm/s and above.
• Accuracy: from ±1.5% and better.
• Output signal type: analog (4–20 mA), digital (Modbus, RS-485).
• Design: dust and moisture protection (IP65 and above).
• Installation: built-in, immersion, portable models.

For systems where flow direction determination is important, it is worth choosing models with reverse air flow detection functionality.

When choosing, pay attention not only to cost but also to compatibility with your systems, durability, and the possibility of integration into automated control systems (ACS TP).

If you are unsure about your choice, submit an application on the website or request a callback. Our specialists will help select equipment that meets your requirements.