The Yokogawa ALF111-S00 is a non-isolating, passive zener safety barrier designed specifically for use with thermocouples in intrinsically safe (IS) applications. Its primary function is to protect hazardous areas by limiting the amount of energy (voltage and current) that can reach the thermocouple, preventing ignition of flammable atmospheres. This model provides a direct, passive signal path for the millivolt (mV) signal from the thermocouple to the safe-area measuring device (e.g., DCS, PLC, recorder) without amplification or conversion. The "-S00" suffix denotes a specific configuration within this series.
