Gravity: Photoelectric Arduino Water Liquid Level Sensor

A photoelectric liquid level sensor that uses optical principles to detect the presence or absence of liquid. With no moving parts, it requires minimal calibration and offers high sensitivity and long service life. The corrosion-resistant polycarbonate probe handles temperatures from −25 °C to 105 °C.

Equipped with a DFRobot Gravity interface adapter, the sensor connects directly to Arduino boards via a Gravity-compatible shield. It also operates at 3.3 V for compatibility with Raspberry Pi and other 3.3 V microcontrollers.

Key Features

• Photoelectric Detection – No mechanical parts, minimal calibration needed
• High Accuracy – ±0.5 mm liquid level detection
• Wide Temperature Range – −25 °C to 105 °C operating range
• Corrosion Resistant – Polycarbonate (PC) construction
• Gravity Interface – Plug-and-play with Arduino Gravity shields
• 3.3 V / 5 V Compatible – Works with Arduino, Raspberry Pi, and other boards
• Long Life – Rated for 50 000 hours

Specifications

• Model – FS-IR02
• Operating Voltage – 5 V DC (also works at 3.3 V)
• Output Current – 12 mA
• Low Level Output – < 0.1 V
• High Level Output – > 4.6 V
• Detection Accuracy – ±0.5 mm
• Dimensions – 28 × 28 mm
• Cable Length – 450 mm
• Weight – 26 g

Ideal For

• Water level monitoring in tanks and reservoirs
• Overflow and dry-run protection systems
• Aquaponics and hydroponics automation
• Arduino and Raspberry Pi liquid sensing projects

Package Contents

• 1× FS-IR02 Liquid Level Sensor Probe
• 1× Gravity Interface Convert Board

Resources

• DFRobot Wiki – FS-IR02 Liquid Level Sensor