P&F Dual Channel Zener Diode Barriers Using a dual channel barrier impedes a direct grounding of the intrinsically safe circuit. The ground is only made in the event of a failure, if the zener diodes conduct. This circuit also suppresses influences of external circuits. Typical application - thermocouples Isolation Barriers Pepperl+Fuchs shunt zener diode barriers are for use as safety interfaces between intrinsically safe and non-intrinsically safe circuits. They are manufactured from Makrolon® and designed to conduct electrical signals - in either direction - between safe and hazardous areas and to limit the amount of energy which can be transferred from a safe to a hazardous area in the event of fault conditions occurring in the safe area. All systems shown are licensed for [EEx ia] IIC Class 1, Div1, Groups A-G