KATU|FS220 Electronic digital display flow switch
KATU|FS220 Electronic digital display flow switch
The FS220 series electronic flow switch is an intelligent flow monitoring instrument designed based on the thermal measurement principle. Its core working principle is as follows: The probe contains a heating element and two precise temperature sensors. One sensor is used to measure the medium temperature, while the other detects the heat conduction effect between the heating element and the medium. When a fluid (liquid or gas) flows through the probe, it takes away the heat from the heating element, resulting in a temperature difference between the two sensors. This temperature difference is proportional to the flow rate (or mass flow rate) of the fluid. The built-in sensing element converts this temperature difference signal into an electrical signal, which is amplified, filtered, and linearly corrected by the subsequent signal processing circuit, and then outputs a standard industrial electrical signal (PNP/NPN switch quantity). At the same time, it drives a high-brightness LED digital display to show the current flow value in real time.
The product adopts an integrated injection molding housing, with a compact structure and good sealing. The protection level reaches IP67, and it can be widely applied in various industrial sites. The 330° rotatable dial is convenient for users to observe at any time. Users can conveniently set the switch point, response time, etc. through the panel buttons, and support various process connection methods (threads, flanges, etc.), flexibly adapting to the installation requirements of different pipeline systems.
PNP/NPN output can be switched, and normally open/normally closed can be set. It is compatible with various PLCs and industrial control systems. The switch load capacity is ≤ 200mA.
The response time can be adjusted from 1 to 13 seconds. It can be flexibly set according to different media (water, oil, air) and working conditions to ensure monitoring accuracy.
IP67 protection level, dust-proof and water-proof, suitable for humid and dusty harsh industrial environments.
Medium temperature -20 to 85℃, environmental temperature -20 to 80℃, storage temperature -30 to 80℃, meeting various process conditions.
The sensing probe and process connection parts use stainless steel 304, which is corrosion-resistant and anti-aging; the shell is made of engineering plastic, lightweight and durable.
Built-in reverse phase, overload, and short circuit protection, improving system reliability and safety.
Using M12×1 standard connector for wiring, supporting various process connection methods, simplifying on-site wiring.
High-brightness LED digital tube displays the flow value in real time, facilitating on-site inspection and parameter setting.
With 24Vdc power supply, the maximum idle current consumption is only 30mA, energy-saving and efficient.
Monitors the flow status of pipelines, used for pump start-stop protection, filter blockage alarm, reverse flushing process control, etc.
Monitors the flow of cooling water, chilled water, and air to achieve energy-saving optimization, fault warning, and interlock control.
Applied in hydraulic lubrication systems, cutting fluid circulation, and flow monitoring of cooling systems to ensure equipment normal operation.
Suitable for flow monitoring of corrosive liquids or gases, providing over/under flow alarms to ensure process safety.
Monitors the flow of cleaning media (CIP) and during raw material transportation processes to meet hygiene standards and process automation.
Such as compressor cooling systems, heat treatment equipment, spraying equipment, semiconductor manufacturing, etc., where flow monitoring of liquid or gas media is required.





![Meeting the Cooling Imperative of the AI Era: [KATU] Full-Range Sensors Empower High-Quality Liquid Cooling Development.](https://ecdn6.globalso.com/upload/p/3850/image_other/2026-06/cover-9.jpg)
![[Katu Electronics (Kunshan) Co., Ltd.] Four-series sensors | CE dual certification](https://ecdn6.globalso.com/upload/p/3850/image_other/2026-09/cover-11.jpg)




