Sensor Technologies Overview

Inductive Sensors

• Technology: Utilize electromagnetic fields to detect metallic objects. When a metal approaches, the inductance of the sensor's coil changes, triggering a response.
• Advantages
• High reliability and durability in harsh environments (dust, dirt, moisture).
• Excellent for detecting metallic objects at close ranges.
• Limitations:
• • Only effective with conductive materials.​
  • Limited sensing range compared to other technologies.

Capacitive Sensors

• Technology: Detect changes in capacitance caused by the proximity or presence of objects (metallic or non-metallic). The sensor's dielectric constant changes with the object nearby.
• Advantages
• • Can detect a wide range of materials, including plastics, liquids, and wood.
  • Adjustable sensitivity allows for fine-tuning to specific applications.
• Limitations:
• • Susceptible to false triggering from environmental factors (e.g., humidity or dust).
  • Shorter detection range compared to optical sensors.

Opto-Electronic Sensors

• Technology: Use light (visible or infrared) to detect the presence or absence of objects. Common types include through-beam, retro-reflective, and diffuse sensors.
• Advantages
• • Non-contact detection with high precision over long distances.
  • Can detect both metallic and non-metallic objects without physical contact.
• Limitations:
• • Performance can be affected by dust, smoke, or reflective surfaces.
  • Require careful alignment and maintenance of the optical system.

Overview

Feature	Inductive	Capacitive	Opto-electronic
Sensing Range	Short (up to a few cm)	Short (up to 10 cm)	Long
Detectable Materials	Metals only	Metals, non-metals, liquids	Any material
Environmental Resistance	Excellent	Moderate	Moderate
Precision	Moderate	Moderate	High
Cost	Low to moderate	Low to moderate	Moderate to high
Applications	Metal detection	Liquid level, plastics	Object detection, positioning

 Any material