Cost-effective operation requires trouble-free unattended work with high sample throughput and minimum downtime – 24/7. Important system components and operations like furnace, filter, drying etc. must be checked and maintained carefully by trained personnel in short intervals to ensure this. But this costs valuable operation time. The auto-protection system of the elemental analyzer multi EA 5000 automatically monitors the drying and cleaning of the reaction gas. If maintenance or attention is required, the operator will be informed by the system itself. This safes valuable operation time and reduces maintenance interventions to an absolute minimum. In addition auto-protection safeguards the entire analyzer by trapping harmful particles and aerosols. It prevents also back-flush of scrubber solutions (H2SO4) and electrolytes in case of power failure in chlorine analysis.