A simple, rugged way to detect a part, Limit Switches operate by physical contact between the object and sensor – frequently with a roller/lever mechanism. These are very cost-effective and easy to apply and maintain, and find their way into extremely harsh, dirty environments.
Safety (Interlock) Door Switches
Safety Door Switches come in a variety of shapes, but the basic premise is to monitor and/or control user access to a hazardous part of a machine or process. They can be a coded-magnet sensor for simple, reliable detection of door open/closed status, or tongue-style switches that can include powered solenoid-locking functions to lock a user out of a given area while a dangerous process is being performed.