Utilized as a no-touch method to provide either precise distance measurement to an object or simple “there/not there” logic, proximity sensors span a wide range of technologies, each offering their own set of operating principles, advantages, and drawbacks. Some of the most commonly found technologies in portable or small embedded systems include ultrasonic, photoelectric, laser rangefinder, and inductive.
Although each technology can serve a variety of different applications, there is no one technology that is suitable for every job. Factors such as cost, detectable range, size, refresh rate, and material effect are all important to consider, while having knowledge of each technology’s basic operation as well as their pros and cons will make the selection process easier.
This CUI Insights blog post, “Comparing Proximity Sensor Technologies” studies ultrasonic, photoelectric, laser rangefinder, and inductive proximity sensor technologies in further detail, giving engineers a solid comparison of their benefits and tradeoffs.