Magnetic Float Sensor FS37A (Vertical)

📌 What Is a Magnetic Float Sensor (Vertical)?
A magnetic float sensor (or float switch) is a liquid level detection device that opens or closes a switch based on the height of a liquid.
It works using a magnet inside a floating body that moves with the liquid level. As the float rises or falls, it activates an internal reed switch inside the stem.
Vertical float sensors are typically mounted vertically in tanks or containers to measure level changes.
🔍 Key Features
Simple Mechanical Design: No need for external power; it functions as a mechanical switch.
Digital Output: Acts as a digital on/off switch depending on liquid level.
NO/NC Switch Configurable: By changing the orientation of the float, you can set it as Normally Open (NO) or Normally Closed (NC).
Compact & Lightweight: Small physical size (~45 × 17 mm) and light weight (≈50 g).
Low Current Capacity: Can switch small currents (~0.5 A maximum) — suitable for interfacing with relays or controllers.
Voltage Handling: Usually capable of switching up to ~220 V AC in simple applications (relay recommended for higher loads).
⚙️ How It Works
The float contains a magnet that moves up and down with liquid level changes.
Inside the stem (vertical tube), there’s a reed switch sealed inside.
When the float magnet approaches the reed switch, it closes the switch (or opens it, depending on orientation).
The switch output can be read by a controller, alarm, pump circuit, or relay to activate actions (e.g., turn pump ON/OFF).
🧪 Typical Specifications (General)
Sensor Type: Magnetic float level switch (reed switch based).
Output: Digital open/close contact.
Contact Rating: ~10 W power handling.
Switching Voltage: Up to ~220 V AC (for simple loads).
Switching Current: Around 0.5 A maximum (use a relay for higher loads).
Contact Resistance: Low (≈100 mΩ).
Dimensions: Compact vertical body (~45 × 17 mm typical).
Weight: ~50 g.
📌 Common Uses
Water Tank Level Monitoring: Detect high/low water levels to control pumps.
Aquarium and Pond Level Control: Trigger alarms or control devices based on water level.
Hydroponics & Gardening Systems: Monitor solution levels.
Household & Industrial Applications: Used in filtration, heating systems, ice machines, and fluid handling.
⚠️ Important Notes
Drive Load with Relay: The sensor can only directly switch small currents; for motors or high loads, use a relay or contactor.
Mounting Orientation Matters: Designed for vertical installation — ensure proper positioning for accurate level detection.
Float Position Changes Output: Flipping the float or sensor orientation can change between NO and NC.