FS-IR02B Photoelectric Liquid Water Level Sensor - Optical Switch 14mm Diameter, 5V

Specifications

• Model: FS-IR02B
• Working Voltage: 5V DC
• Output Current: 15mA
• Working Temperature: -25°C to +105°C
• Detection Principle: Photoelectric (Infrared Reflection/Refraction)
• Thread Diameter: 14mm
• Wire Length: ~50cm
• Housing Material: Durable Polycarbonate
• Response Time: <500ms

Key Applications & Projects

• Smart Home: Automatic coffee machine water level monitoring.
• Industrial: Low-level alarms for coolant tanks or chemical reservoirs.
• Hydroponics: Maintaining precise nutrient levels in vertical farming setups.
• Aquariums: Auto-top-off (ATO) systems to maintain water salinity levels.

Project Evolution

• Past Projects: If you've mastered basic IR obstacle sensors or mechanical float switches, this is your next step.
• Feature Upgrade: The FS-IR02B unlocks professional-grade liquid detection that is immune to corrosion and mechanical jams, making your project viable for long-term deployment.
• Effort Level: Intermediate. Requires a basic understanding of analogue/Digital input pins.

Virtual Technician & Wiring

⚠️ Safety Warning: Ensure the sensor is mounted vertically for the most accurate readings. Avoid placing it directly under a bright light source which may interfere with the optical detection.

Pin Mapping:

• Red Wire: VCC (5V)
• Blue Wire: GND (Ground)
• Yellow Wire: Signal Output (Low in liquid, High in air)

Package Includes:

• 1 x FS-IR02B Photoelectric Water Level Sensor

Frequently Asked Questions (FAQ)

• Is the FS-IR02B waterproof? Yes, the sensing head is fully sealed for immersion.
• Can it detect liquids other than water? Yes, it works with most clear or translucent liquids.
• What is the mounting hole size? It requires a 14mm diameter hole.
• Does it work with 3.3V logic? It is rated for 5V; use a level shifter for 3.3V MCUs like ESP32.
• Is it affected by steam? Minor condensation does not affect it, but heavy steam might.
• Can it be used in pressurized tanks? It is designed for atmospheric pressure environments.
• Does it have moving parts? No, it is entirely solid-state photoelectric.
• What is the output signal type? It provides a digital High/Low signal.
• Can it detect oil? Yes, provided the oil is not too dark or opaque.
• Is the sensor food-grade? It is made of polycarbonate, but check specific chemical compatibility for food applications.
• How long is the cable? Approximately 500mm.
• Can the cable be extended? Yes, standard 3-core wire can be used.
• Is the nut included? Yes, it comes with the mounting nut and silicone washer.
• What is the lifespan? Rated for >50,000 hours of operation.
• Can it be used in salt water? Yes, unlike metal sensors, it is resistant to salt corrosion.
• How do I clean the sensor? Wipe the tip with a soft cloth and IPA if residue builds up.
• Is it sensitive to sunlight? Avoid direct sunlight on the sensing head to prevent false triggers.
• Can I use it with Arduino? Yes, it connects directly to any digital I/O pin.
• What is the current consumption? Very low, typically around 15mA.
• Is it normally open or normally closed? The output is Low when liquid is detected.