Air Concept - A01 Air Quality Performance Test Carbon Monoxide Applies to Part 3- Meet Thresholds for Inorganic Gases Test Method Minimum of one continuous hour (10 minutes of acclimation time followed by 50 minutes of measurement time), with measurements recorded at least once every minute. Reporting & Compliance Compliance is based on the median value collected during the measurement time at each sampling compared with the WELL requirements. Device Requirements Real-time direct reading instrument. Measurement range: 0-25 ppm Instrument resolution: 0.1 ppm On-screen resolution: 1 ppm Lower detectable limit: 0.1 ppm Calibration: instrument must be within the calibration period