Generic Optical Liquid Level Sensor - 5V DC, 50cm Cable, Locking Nut Mount

The sensor is designed for a nominal 5V DC operation. It is critical to stay within the specified voltage range (typically 4.5V to 5.5V) to ensure proper IR LED function and prevent damage to the internal phototransistor circuit. Exceeding this voltage can cause permanent failure.

Connect the sensor's red wire to 5V, the black or brown wire to GND, and the blue or yellow signal wire to a digital input pin on your microcontroller. The output acts as a switch: it will be in one logic state (HIGH or LOW) when dry and flip to the opposite state when submerged. A pull-up or pull-down resistor may be required depending on the sensor's internal configuration.

This is strictly a point-level detection sensor. It provides a digital on/off signal indicating whether its tip is in air or liquid. It cannot provide analog output or measure varying liquid heights. For continuous level measurement, consider an ultrasonic, capacitive, or pressure-based sensor.

It is designed primarily for clear, non-viscous liquids like water, aqueous solutions, and certain coolants. The sensing principle relies on a change in refractive index. Opaque, cloudy, or highly viscous fluids may not reliably change the internal light reflection, leading to detection failure. Always verify chemical compatibility with the sensor's housing material (typically PPS plastic).

Install the sensor by inserting its threaded body through a drilled hole in your tank or reservoir wall. Use the provided locking nut on the outside to secure it tightly, ensuring the sensor tip protrudes into the liquid at the exact level you wish to monitor. A sealing washer may be needed to prevent leaks; ensure the installation maintains any required IP rating.