A fluid analyzer having an electrical heater includes an intrinsic safety barrier that provides voltage and current from a power source to an electrical load and includes a voltage limiter and an infallible current limiting resistor for limiting the voltage and current provided to respective intrinsically safe levels, where the voltage limiter is arranged in a flameproof/explosion proof or pressurized/purged enclosure, and the current limiting resistor, e.g., an electrical heater, is connected via a connecting line to the voltage limiter and arranged outside the flameproof/explosion proof or pressurized/purged enclosure in an enclosure configured to provide protection against contact and ingress without being flameproof/explosion proof or pressurized/purged.