Magnetic Float Sensor FS37A (Vertical)

Reliable vertical-mount magnetic float sensor for precise liquid level detection. The FS37A uses a magnetic reed switch mechanism to provide clean, accurate switching as the float rises and falls with the liquid surface - ideal for water tanks, sumps, aquariums, and automated fluid management systems.

Specifications

Why Choose the FS37A?

• Simple & Reliable: No electronics inside the sensor - the magnetic reed switch provides dependable, bounce-free operation with no power consumption at idle
• Easy Vertical Installation: Threaded stem mounts through a tank wall or lid with included nut for secure, leak-resistant fitting
• Microcontroller Friendly: Two-wire output connects directly to Arduino, ESP32, Raspberry Pi, or any digital input - just add a pull-up resistor
• Chemical Resistance: Polypropylene float withstands water, mild chemicals, and common household liquids without degradation
• Compact Form Factor: Small enough for aquariums and hobby projects, robust enough for overhead water tanks and industrial sumps
• 100% authentic from trusted suppliers
• 1-5 day shipping, 7-8 day delivery from Bengaluru warehouse
• Expert technical support included

How It Works

The FS37A consists of a fixed stem containing a magnetic reed switch and a buoyant float with an embedded magnet. When the liquid level rises, the float slides upward along the stem, bringing the magnet close to the reed switch and causing it to close (conduct). When the level drops, the float descends, the magnet moves away, and the switch opens. This provides a simple HIGH/LOW signal indicating whether the liquid has reached the sensor's trigger point.

Project Ideas

• Automatic Water Tank Controller: Mount in your overhead or underground tank to trigger a pump on/off based on water level - use two sensors for high and low thresholds
• Aquarium Auto Top-Off: Detect evaporation-driven water level drops and automatically activate a dosing pump to maintain consistent water levels
• Sump Pit Overflow Alert: Install in a basement sump pit to send alerts via buzzer or IoT notification (ESP8266/ESP32) when water rises to dangerous levels
• Coffee Machine / Beverage Dispenser: Monitor reservoir levels and display refill warnings on an LCD or trigger automatic refilling
• Hydroponics & Irrigation: Maintain nutrient solution levels in hydroponic reservoirs or detect when irrigation tanks need refilling
• IoT Water Monitoring Dashboard: Pair with an ESP32 and Blynk/ThingSpeak to remotely monitor tank levels from your phone with historical logging
• Learning & Education: Excellent hands-on component for teaching digital inputs, pull-up resistors, interrupt-driven programming, and sensor interfacing

Wiring Guide

The FS37A has two wires (no polarity). Connect one wire to a GPIO pin on your microcontroller and the other to GND. Enable the internal pull-up resistor on your GPIO pin (or add an external 10kOhm pull-up to VCC). When the float is down (low liquid), the switch is open and the pin reads HIGH. When the float rises (high liquid), the switch closes and the pin reads LOW.

Arduino Example:

• Wire 1 -> Digital Pin 2
• Wire 2 -> GND
• Enable INPUT_PULLUP on Pin 2 in code
• digitalRead(2) returns LOW when liquid level is high

What's in the Box

• 1x Magnetic Float Sensor FS37A

Frequently Asked Questions

Buy Magnetic Float Sensor FS37A (Vertical) Online in India

Purchase the Magnetic Float Sensor FS37A (Vertical) online at The Tech Depot - India's most trusted electronics components store. We deliver across all major cities including Bengaluru, Mumbai, Delhi, Chennai, Hyderabad, Pune, Kolkata, Ahmedabad, Jaipur, and Surat. Get the best price on Magnetic Float Sensor FS37A (Vertical) with fast 1-5 day shipping from our Bengaluru warehouse. All products are 100% authentic, sourced from authorized distributors with 7-day warranty on manufacturing defects.

Looking to buy Magnetic Float Sensor FS37A (Vertical) at the best price in India? The Tech Depot offers competitive pricing, bulk discounts for orders of 10+ units, and dedicated technical support via email and WhatsApp. Whether you are a hobbyist, student, or professional engineer, we have everything you need for your electronics projects.