Portable indoor air monitor with lab quality accuracy for comprehensive indoor environment assessments, using a multi-sensor fusion algorithm and designed to not interfere with other devices. Advanced multi-detection with precise monitoring of formaldehyde (HCHO) and TVOC levels using electrochemical and semiconductor sensors, with immediate data logging. SEN+-calibration technology, temperature compensation, and LED refresh within 5 seconds for stable ambient air analysis. Compact plug-and-play design for living rooms, renovated spaces, schools, or temporary workplaces without installation requirements. Use scenarios: - After home renovation, verify indoor air safety before occupants return. - In classrooms, monitor VOCs during occupancy to maintain healthy air. - In temporary offices or pop-up spaces, ensure consistent indoor air quality.