Ultrasonic Sensors Challenge On/Off Proximity Types

Combining a very short deadband with an easy-to-mount, 18-mm barrel package, the SUPERPROX SM600 Series of ultrasonic sensors is said to provide an economical alternative to on/off proximity sensing. Unlike inductive prox sensors, which must almost touch the object being detected, these ultrasonic devices can be "backed off" by 25.4 to 305 mm from the object, enabling engineers to position them out of harm's way in harsh environments.
The tamper-proof sensors are configured at the factory for a specific sensing range, as well as to fix the sensing "window", which can be as narrow as 3.2 mm. The ultrasonic sensors can detect objects of all colors and materials as small as 1.6 mm diameter at distances of 63.5 mm. And they operate on 12 to 24 vdc and, among other things, offer a green LED to indicate power on and an amber LED to indicate when the object is detected within the fixed window.