What is a signal isolator and why is it important?

A signal isolator provides galvanic separation between input and output circuits while transmitting the signal value. Benefits: breaks ground loops (eliminates noise from ground potential differences), protects equipment (prevents fault propagation), safety barrier in hazardous areas, and eliminates noise from common-mode interference. Isolation methods include transformer coupling, optical coupling, and capacitive coupling. Isolators are essential when connecting equipment with different grounds, in hazardous area installations, and for noise-sensitive measurements.