This sensitive, single-setpoint  motion sensor system can be used even in hazardous,high temperature, and harsh conditions because of its superior sensing probe design. The system protects equipment by detecting absence of motion, as well as underspeed or overspeed conditions.

Milltronics Millpulse 600
This heavy-duty 2-wire motion sensor provides a solid state switch output to PLCs when monitoring speed of rotating , reciprocating or conveying equipment.