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The Optomax is an optical liquid level sensor that detects the presence or absence of almost any liquid — oil or water based. Inside the polysulfone housing,...

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The Optomax is an optical liquid level sensor that detects the presence or absence of almost any liquid — oil or water based. Inside the polysulfone housing, an infrared LED and matching phototransistor work together: when dry, the IR light reflects internally back to the sensor; when the tip is immersed in liquid, the light escapes and the output switches.

The sensor provides a push-pull digital output capable of sinking or sourcing up to 100 mA, allowing it to directly drive small loads like transistors or relays. It operates on 4.5–15.4 V DC and is insensitive to ambient light, foam (when in air), and small bubbles (when in liquid).

Key Features

  • Optical Sensing – No moving parts for reliable, maintenance-free operation
  • Push-Pull Output – Sinks or sources up to 100 mA for direct load driving
  • Wide Supply Range – 4.5–15.4 V DC with reverse polarity, ESD, and transient protection
  • Chemical Resistant Housing – Polysulfone construction for use with a wide range of fluids
  • Compact Form Factor – Suitable for space-constrained installations
  • Leak Detection Capable – Sensitive enough to detect small amounts of liquid when positioned correctly
  • Fast Response – Repeatable switching point with optional output delays for sloshing applications

Wiring

  • Blue/Black Wire – Ground
  • Red Wire – Supply voltage (4.5–15.4 V DC)
  • Output – Supply voltage when dry, 0 V when wet

Specifications

  • Output Type – Push-pull, up to 100 mA sink/source
  • Supply Voltage – 4.5–15.4 V DC
  • Housing Material – Polysulfone (chemically resistant)
  • Operating Temperature – −25 °C to 80 °C
  • Detection – Oil and water-based liquids

Package Contents

  • 1× Optomax digital liquid level sensor
Note: The sensor is highly sensitive — any liquid on the sensing tip (including droplets) can trigger detection.

Jargon buster

Plain-language definitions for the technical terms used above.

DC
DC means direct current, where electricity flows in one constant direction, as supplied by batteries, USB ports and many plug-pack power supplies. When a product specifies DC, it runs from a DC supply rather than mains AC, so you need to provide the correct voltage and polarity.
LED
A light-emitting diode (LED) is a small electronic component that emits light when current flows through it in the correct direction. Because it only conducts one way, its polarity matters, and a through-hole LED must be soldered the correct way around to light up.
phototransistor
A light-sensitive transistor that changes its electrical output when light hits it. Compared with a modulated IR receiver, a simple phototransistor can be more affected by ambient light, so it may need extra filtering or careful setup.
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