An Analog Proximity Sensor is a type of proximity sensor that doesn’t just say “object detected” or “not detected” like a normal (digital) proximity sensor — instead, it provides a continuous output signal (voltage or current) that varies according to the distance between the sensor and the object.

How it works

  1. Sensing Principle
    The sensor can be based on different technologies — inductive, capacitive, ultrasonic, or optical — but instead of producing a binary ON/OFF signal, its electronics convert the sensing changes into a proportional analog signal.

  2. Continuous Measurement

    • The closer the object, the higher (or lower) the output voltage/current.

    • Output is often 0–10 V, 1–5 V, or 4–20 mA.

  3. Real-Time Feedback
    This allows the connected system (like a PLC) to know exactly how far an object is, within the sensor’s range.

Key Features

  • Distance measurement within the sensing range, not just presence detection.

  • Higher precision compared to simple digital sensors.

  • Can be inductive, capacitive, ultrasonic, or laser-based.

  • Often requires calibration for best accuracy.

Common Applications

  • Position feedback for robotic arms.

  • Monitoring the fill level of a tank or hopper.

  • Measuring displacement in machine tools.

  • Detecting and tracking moving parts on conveyors.

💡 Quick example:
In an automated bottling machine, an analog ultrasonic proximity sensor can measure how high the liquid is inside each bottle and adjust the filling nozzle in real time.