Proximity, photoelectric, position, and force sensor types for automation and robotics. Filter by category and search by what you need to detect.
Choosing the wrong sensor technology for the physical conditions — metal vs. non-metal target, dusty/wet environment, required range — is one of the most common causes of unreliable automation systems. This reference summarizes the main sensor families and what each is actually good at.
Proximity sensors (inductive, capacitive) are short-range and contactless, ideal for machine and cylinder position sensing where the target is close and the environment may be dirty. Photoelectric sensors use light and can operate at much longer range, but the three configurations (through-beam, retroreflective, diffuse) trade off installation complexity against reliability, so the choice depends on both the required range and how much wiring complexity the application can tolerate.
Use inductive if the target is metallic and the environment is dirty, oily, or dusty, since inductive sensing is immune to non-metallic debris. Use capacitive if the target is non-metallic (plastic, liquid, powder, glass) or if you need to sense through a non-metallic container wall, accepting shorter range and more sensitivity to humidity.
Through-beam sensors offer the longest range and are largely immune to target color, surface finish, or reflectivity, making them the right choice when reliability matters more than installation simplicity. Diffuse sensors are easier to install (one unit, no reflector) but are the least reliable of the three photoelectric configurations because detection range depends heavily on the target's own surface properties.